In the last article that Max Vachon devoted to the register of students 
attending Lamarck's lectures, he announced: "I propose to publish the list of 
all the auditors in the Mémoires of the Muséum. Historians of science can thus 
complete my data and find out who they were, who they became and, perhaps, find 
among their family or social relations zoologists or philosophers who had a good 
knowledge of the work of Lamarck" (18).   The fact that M. Vachon did not 
publish the result of his work (several drafts were underway when he died) 
reflects the problems that the state of the register poses for publication and 
for research. If one keeps to the basic issue of establishing the number of 
attendants, without speculating on the signatures that have been cut out and 
making allowance for repetitions, the numbers given by M. Vachon in the two 
articles he wrote on the subject present substantial variations. Thus, out of a 
total of 1,108 (plus 124 who followed the course during the replacement of 
Lamarck by Latreille in the years 1821-1823), in his contribution to the volume 
Lamarck et son temps Vachon gives the number of 167 foreigners, whereas in the 
article "Lamarck et son enseignement au Muséum" they are reduced to 141. After 
working for six months on the register and on the transcriptions made by MM. 
Vachon and Rousseau, I hesitate to give my own figures: many signatures are 
typically the result of rapid strokes, of difficult and sometimes impossible 
reading. The several cases of slightly different first names with the same 
surname (brothers or preference for one or another variant of one person's 
name?) prevent us from attempting precise calculations, which remain inevitably 
doubtful without further research. Additionally, some of the signatures of 
non-French members of the audience have been incorrectly deciphered: I could 
mention, to give a couple of examples, the case of Leopoldo Fabroni, whose 
signature is transcribed by Vachon and Rousseau as "Fabioni", or Giuseppe 
Marzari Pencati, read as "Joseph Marzani". Yet, it is far from my intention to 
criticise the work of our predecessors : on the contrary, the fact that I have 
noticed these differences for Italian authors I have already studied, emphasises 
the necessity of a research project involving historians of biological sciences 
and general historians from all the countries represented in the register by one 
or more signatures. It is clear that in many cases, only direct familiarity with 
the signature or with the name of the person will allow reliable 
identifications. 

(18) M. Vachon, 1981, pp. 242-243.