German anatomist Max Clara (1899–1966) described the “Clara cell” of the bronchiolar epithelium in 1937. The present article investigates Clara's relationship with National Socialism, as well as his use of tissue from executed prisoners for research purposes, details about both of which are largely unknown to date. Our methodology for the present study focussed on analysis of material from historical archives and the publications of Clara and his co-workers.
Clara was appointed as Chair of Anatomy at Leipzig University (Leipzig, Germany) in 1935. He owed his career, at least in part, to Nazi support. He was an active member of the Nazi party (Nationalsozialistische Deutsche Arbeiterpartei (NSDAP)) and engaged in university politics; this included making anti-Semitic statements about other academics in appointment procedures. Nevertheless, he also supported prosecuted colleagues.
Much of Clara's histological research in Leipzig, including his original description of the bronchial epithelium, was based on tissue taken from prisoners executed in nearby Dresden (Germany).
Max Clara was an active and outspoken Nazi and his histological research exploited the rising number of executions during the Nazi period. Clara's discovery is thus linked to the Nazi system. The facts given in the present paper invite discussion about the eponym's neglected history and its continued and problematic use in medical terminology.
In 1937, anatomist Max Clara described a new secretory cell type in the human bronchial epithelium 1; this has been known as the “Clara cell” since at least 1955 2. With the identification of a specific Clara cell protein (CC10, identical to CC16 or uteroglobin) 3, which may play a role as a clinical biomarker of lung disease 4, and with the characterisation of a Clara-like cell in neuroepithelial bodies of the airway lining 5 in the 1980s, interest in the cell and its function has intensified. The term “Clara cell” has been in widespread international use since that time (fig. 1).
At the same time, there has been considerable interest in eponymous scientific discoveries by researchers with a connection to Nazi Germany, such as Hans Reiter 7, Friedrich Wegener 8, Julius Hallervorden and Hugo Spatz 9. It is therefore surprising that Clara's documented support of the Nazi movement 10, 11 has not drawn more attention, particularly as his oft-cited original description 1 was based on tissue taken from executed prisoners, a material source that is dubious at best by today's ethical standards. We have therefore attempted to clarify Clara's involvement in National Socialism and the ethical context of the original description of “his” cell. To our knowledge, no other eponym in respiratory medicine, with the exception of Wegener's granulomatosis (see Discussion), originated in the Third Reich.
We examined relevant literature, documents held in historical archives in Berlin, Leipzig, Dresden, and Munich (all Germany), and the publications of Clara and his co-workers. As some of the documents referred to in this manuscript may be difficult to find, these have been provided online as supplementary material. The relevant references are marked with an asterisk (*). For all other documents of this kind, the reader should refer to the institute holding the archive.
Max Clara's career
Max Clara (fig. 2) was born in 1899 in a village near Bozen in South Tyrol, then part of Austria. Having studied medicine in Innsbruck, Austria, and Leipzig, Germany, Clara's first position was at the Institute of Histology and Embryology in Innsbruck in 1923. After the sudden death of his father in 1924, Clara left this post to carry on his father's general practice in his home village, which had come under Italian rule in 1919. He continued his histological research in his spare time and, from 1929 on, also lectured in an unpaid position at the University of Padua (Padua, Italy) 12.
In 1935, to the annoyance of established anatomists 13*, Clara was appointed Chair of Anatomy at Leipzig University, and in October 1942, assumed the prestigious position of Chair of Anatomy in Munich, which he held until the end of the war. Like many other Nazi Party members in public office, Clara was arrested by the US army in October 1945 14*. After his release in October 1946, Clara could not find a permanent position at Munich University or elsewhere in Germany despite many desperate efforts 15*. His status within German academia after 1945 seems to have been one of persona non grata (dicussed further later). In 1950, he finally accepted a professorship for histology at the University of Istanbul, Turkey, which he retained until 1961 16. Max Clara died in Munich in 1966.
Clara and National Socialism
While Clara was undoubtedly an accomplished histological researcher, he had virtually no experience in gross anatomy on taking up his first professorship in Leipzig in 1935. Many sources show that his striking career advancements in 1935 and 1942 were largely due to political support within the Nazi establishment, including the SA (storm troopers) and Max de Crinis, a prominent Nazi physician at the Ministry of Higher Education 13*, 17*, 18*, 19, 20*]. De Crinis (1889–1945) held the Chair of Neurology and Psychiatry of Charité Medical School in Berlin from 1939. He was centrally involved in SS activities and is widely regarded as a key figure in the Nazi “euthanasia” programme, in which tens of thousands of psychiatric patients were murdered 21.
Immediately on arriving in Leipzig from Italy, Clara joined the NSDAP (National Socialist German Worker's Party; membership number 3610105) 22*. His inaugural address in Leipzig, attended by representatives of all NSDAP organisations and held “not in tails, but in simple brownshirt” 23, was a political demonstration rather than an academic ceremony. His speech, published in a well-known general medical journal, explicitly welcomed the “National Socialist revolution of 1933” and urged scientists to “join the marching columns of our Führer” 10.
From 1936 to 1942, Clara actively participated in the Nationalsozialistischer Deutscher Dozentenbund (National Socialist German League of Lecturers). He was the League's branch head (Dozentenbundsführer) for Leipzig University, and also Acting District Head (kommissarischer Gaudozentenführer) of Saxony from late 1941. To our knowledge, Clara never joined any other NSDAP suborganisations, such as the SA or the SS. The organisation Dozentenbund was founded in 1935 to represent NSDAP interests within academia and to foster the development of National Socialist science 24. While the content of Clara's scientific publications was not political and did not contribute to a racist or anti-Semitic “pseudoscience”, he actively participated in university politics, which included providing politically biased appraisals for scholarships, intimidating dissenting colleagues 25 and influencing appointment procedures. For example, in 1937, Clara's appraisal prevented the appointment of Gerhard Gesemann from Prague (Czechoslovakia) to the newly founded position of Chair for Slavonic Studies in Leipzig; Clara's 16-page expert assessment accused Gesemann of collaboration with Jewish professors, thus going “against the concept of the Nordic Race” 19, 26*.
In another appointment process, for the Chair of Otorhinolaryngology in Leipzig, Clara favoured a different candidate to that of the local NSDAP Gauleiter (district leader). The subsequent quarrel with the powerful and autocratic Gauleiter resulted in an official reprimand of Clara by the Supreme Party Court in September 1942, a ruling mitigated but upheld in an appeal hearing in February 1943 27*. We do not know whether this ruling had any consequences for Clara.
As Gaudozentenführer, Clara wrote an introduction to a national academic directory of 1942, in which he stated “with pride that science has contributed to the great plans of the Führer” and called for scientists to submit to the reigning ideology and to be ready to secure the German claim to European leadership “intellectually as much as by the politics of force” 11. Clara also agitated for the NSDAP in the Anatomische Gesellschaft, the society of German-speaking anatomists. In 1939, he and the outspoken National Socialist Eduard Pernkopf formed half of the four-member executive committee 28. The Viennese anatomist Pernkopf is well-known for his anatomical atlas, which has recently been proven to be based, at least in part, on specimens from executed Nazi victims 29. Clara's and Pernkopf's attempts to transform the Anatomische Gesellschaft into a National Socialist organisation met with resistance and had limited success 30, and Clara's name does not appear in its membership lists after the post-war re-establishment of the society in 1949. This, as much as his futile search for a post after 1946, demonstrates that Clara's career, so closely allied with the NSDAP, saw him ostracised in German post-war academia.
The controversial post-war denazification process 31, 32 classified Clara as a Mitläufer (follower) in June 1947, but cleared him upon appeal the following year 33*. Clara had successfully argued that his quarrel with the Gauleiter had been an act of “active resistance” against party leaders, which had eventually led, against his wishes, to his posting to the Chair of Anatomy in Munich in late 1942. This version of the facts is, however, unlikely. First, his remuneration package in Munich was much more handsome than that in Leipzig 14*. Secondly, archived letters from the Ministry of Education demonstrate that Clara actively strived for this post from at least 1941 18*, 20*. Therefore, his posting could also be interpreted as an effective promotion and his alleged “active resistance” against the Gauleiter as a power struggle within NSDAP. But, the Denazification Tribunal did not refer to the mentioned sources and by that time, acquittals by such tribunals were already very common 31.
It should, however, also be noted that the denazification records include additional affidavits describing Clara's support for a “half-Jewish” doctoral candidate prior to 1938 and for fellow anatomist Titus von Lanz, who was prosecuted by the Nazis for having a Jewish wife 34*. Nevertheless, von Lanz later joined his colleagues' efforts to prevent Clara from returning to his post at the Anatomy Dept of Munich University 18*.
Clara's “material” and the Clara cell
In 1937, Clara described a new cell type in the terminal bronchioli, which he characterised morphologically as having secretory granules and a dome-shaped apical surface without cilia (see fig. 1 of the online supplementary material) 1. Clara described the material as “stemming exclusively from executed individuals, who were preserved by vascular injection immediately after death” 1 and added that he assumed this “rather extensive and perfectly fixed material” had given him an advantage over previous researchers. Of Clara's 25 publications between 1935 and 1945 12, nine were based on tissue from executed prisoners. At least 14 papers published by co-workers at his Leipzig institute were also based on such tissue.
The extensive use of bodies of executed prisoners for anatomical purposes was based on the rising number of executions during the Nazi era. However, the bodies of executed prisoners had been used prior to the Nazi regime, and the practice was sanctioned by laws passed as early as 1877. These laws remained in place during the 1930s, with the Nazi authorities merely passing decrees in 1933 and 1939 that regulated the distribution of bodies from specific centralised execution sites to individual anatomical departments throughout the country 30, 35, 36. Clara's institute in Leipzig was regularly allocated bodies from executions in nearby Dresden, where more than 1,300 prisoners were put to death between 1933 and 1945, most for political reasons. Specifically in Dresden, many prisoners had been resistance fighters from Bohemia and Moravia, captured after the German occupation in 1938, and Poland, after its defeat in 1939 37, 38. However, we have been unable to link the names of specific executed prisoners to any of Clara's publications to date.
Clara was not simply a passive recipient of the bodies. Only a week after assuming his post as Director of the Anatomical Institute in Leipzig, he wrote to the Saxon State Ministry of Education urging it to extend laws permitting the use of bodies of executed prisoners. As the law of 1877 still precluded anatomical dissection if the relatives requested the body, Clara now suggested changing the law to allow anatomical dissection regardless of the family's wishes 39*. He also suggested that, until the law was changed, researchers should dissect such bodies regardless of whether they had appropriate authorisation, but camouflage their illegal actions by preserving the external appearance of the bodies, a suggestion supported by the Chief Prosecutor of Dresden 40*.
In March 1936, the Ministry finally consented to dissection even if relatives had requested the bodies, but forbade any removal of organs 41*. This effectively prohibited Clara's histological research if the bodies were indeed claimed by the families, but, given Clara's documented objections, we do not know whether he adhered to the decision. A formal decree stipulating that the families no longer be informed of the execution was only issued in 1942 36. As this regulation led to desperate relatives approaching the anatomical institutes in search of the remains of their loved ones, Clara later suggested to the local prison administration in Munich that the anatomical use of the bodies should not be disclosed at all to the relatives 42*.
Source texts also indicate that Clara 43 and his co-workers 44, 45 experimented on at least one of the prisoners sentenced to execution. To investigate the effect of oral vitamin C uptake on the histochemical localisation of ascorbic acid in cerebral cells, the male was administered vitamin C tablets for 5 days prior to his death 43–45. It is implausible that a prisoner awaiting his execution would be given vitamin C for other reasons than as part of an experiment.
The establishment of the “Clara cell” as eponym
As for the post-war establishment of the term “Clara cell” in medical terminology, it seems that the first authors to quote Clara's original description were Andrew and Burns 46 in 1947. The British authors stated that the cells were “described first by Clara in male and rabbit” and were investigated “in material from executed individuals”; however, they did not refer to the cells by the eponym. To our knowledge, the first to use the eponym, in its French version “cellule de Clara”, was Policard et al. 2 in 1955 in an ultrastructural description of the bronchioli of the rat. It seems that the eponym was then promoted, at least in Germany, by Erich Schiller, a pupil of Clara 47. None of these publications or others from that period which quote Clara's paper 48, 49 contain any indication of a critical stance towards Clara himself or the source of his research material. And while his former colleagues from Munich, in their statement of 1948 (see previous, and 18*) were very critical of Clara's National Socialist engagement, they did not mention his research either. Moreover, Clara himself continued to use the specimens in the post-war period. Even 7 years after the Nazi era, in a publication again based on histological specimens from the war years, his identification of the source of his specimens was limited to the statement: “healthy individuals, who died a sudden death after variable duration of imprisonment” 50.
We have shown that Max Clara was an active and outspoken Nazi. His support of the Nazi system is clearly documented over many years, at least from 1935 to 1942 10, 11. As we have shown, his eventual acquittal by the post-war Denazification Tribunal was erroneous, as some relevant evidence was not considered. Clara's post-war claim to “active resistance” certainly belittles the efforts of true resistance activists.
His original description of the Clara cell in 1937 was based on tissue from executed prisoners. Using the bodies of executed prisoners for research purposes was neither illegal at the time (as long as the relatives did not request the body) nor a practice limited to the Nazi regime 51, 52. However, the growing terrorist aspect of jurisdiction was specific to the Third Reich. It led to an enormous rise in executions, from 1–4 per year before 1933 to about 100 per year after 1933 and to more than 4,000 executions in 1943 53. These numbers do not include military executions, murder by the Gestapo and deaths in concentration and extermination camps.
German and Austrian anatomists benefited from these changes through an unprecedented cadaver supply mainly used for teaching purposes, but also for research 52, 54–56. By making use of the cadavers, they, willingly or not, colluded with a political strategy that sought to eliminate not just dissidence, but also eliminated the very memory of the dissidence, in so far as the executed were denied proper burial 35. This has been described as “moral complicity” with the system 57. As we have shown, Clara not only passively benefited from the increasing “body supply” but actively stretched the legal limits of cadaver use, in cooperation with the legal authorities, by trying to conceal anatomical use of the bodies from the relatives of the executed. We must assume that Clara's collusion with the Nazi strategy to eliminate dissidence was willing.
It seems that Clara's use of the bodies of execution victims was not an issue for his contemporaries, neither during the Denazification Tribunal nor when the eponym “Clara cell” was established. If at all, post-war criticism of this practice was voiced against the anatomical use of the bodies of certain groups of political victims 52. We suppose that many contemporaries accepted the anatomical use of execution victims in principle (as they accepted capital punishment in principle) but objected to treating certain victims like “common criminals”. In contrast to his Berlin colleague Hermann Stieve 52, 58, Clara was never accused of using the bodies of political victims during his lifetime.
However, Clara crossed an additional ethical line by experimenting on at least one of the prisoners prior to execution 43. While the experiment itself was the harmless administration of vitamin C, it demonstrates that Clara regarded this prisoner as little more than a guinea pig. To our knowledge, Clara and his co-workers were the only anatomists using scheduled executions for experiments that involved an intrusion into the life of the prisoner awaiting execution. Comparable experiments were performed by a zoologist in Halle/Saale in 1944, who had two prisoners drink a vitamin A emulsion 6 hours before their execution to study its effects on the retina 59. While such experiments cannot be compared to the gruesome experiments on living inmates performed in some concentration camps, they can be seen as part of what Alexander Mitscherlich, in his report on the Nuremberg doctors' trial, has called “medicine without humanity” 60.
An ongoing debate exists in the literature on whether eponyms should be used at all 61; despite this, the use of eponyms does not seem to be declining. The awarding of an eponym like “Clara cell” is multifaceted. First, putting aside the issue of scientific originality, an eponym is always a tribute to a person. Therefore, the scientific community should discuss whether it wants to honour an outspoken Nazi, as it currently does by using this eponym. Secondly, although the importance and histological expertise of Clara's original description are beyond doubt, the ethical context of this scientific discovery is at best questionable. To our knowledge, the Clara cell is the only “Third Reich eponym”, for which not only the person but the discovery itself is clearly linked to the Nazi system. In the cases of Reiter's disease and Hallervorden-Spatz disease, the eponymous discovery was made long before the Nazi era 7, 9 while Wegener's first description of “his” granulomatosis in 1939 had no connection to Nazi atrocities 8. The challenge associated with these eponyms is based on the personal association of the scientists with the Nazi regime.
Renaming an eponym requires making a clear moral judgement, which is not always straightforward 62. Any appraisal of moral failure from today's perspective is difficult and must consider historical context. The purpose of this paper is not to simply offer such a judgement, but instead to initiate a historically reflective discussion of this eponym.
In our own opinion, a different term would be preferable. As the name assigned to this cell by the official anatomical terminology, “exocrine bronchiolar cell” 63, is a little unwieldy and does not clearly differentiate it from goblet cells, we suggest the descriptive term “club cell”, as used occasionally in German (Keulenzellen) 49 and English 64 publications in the 1950s and 60s.
We thank D. şahin and N. Yesilkus (both Charité – Universitätsmedizin Berlin, Berlin, Germany) for translation from Turkish, and J.A. Liebkowsky (Neuroscience Research Center (NWFZ) Charité – Universitätsmedizin Berlin), and K. Heper (Institute of the History of Medicine, Heinrich-Heine-Universität, Dusseldorf, Germany) for help with the English manuscript.
For editorial comments see page 706.
As some of the documents referred to in this manuscript may be difficult to find, these have been provided as supplementary material. The relevant references are marked with an asterisk (*). For all other documents of this kind, the reader should refer to the institute holding the archive. Supplementary material is accessible from www.erj.ersjournals.com
Statement of Interest
- Received September 15, 2009.
- Accepted February 22, 2010.
- ©2010 ERS