PAPERS OX BIOLOGY AND AGRICULTURE 145 



TESTING LAMARCK'S THEORY 



Casper L. Redfield, Chicago, III. 



The first clear and distinct theory of evolution was ad- 

 vanced by the French scientist, Jean Baptiste de La- 

 marck. With the exception of that of Darwin, the theory 

 of Lamarck has been discussed more than any other, and 

 it is the least understood of any theory which has been 

 discussed at all. Considering the vast literature and al- 

 most total lack of understanding, Lamarck's theory pre- 

 sents what is perhaps the most remarkable case in the 

 history of science. 



The causes leading to the misunderstanding of this 

 theory would fill a book, so we will confine ourselves here 

 to explaining what the misunderstanding is rather than 

 the causes which led to it. To make the matter clear it 

 will be necessary not only to state what the theory is, but 

 to point out what it is not. 



Lamarck's theory is stated in his Zoological Philoso- 

 phy published in 1809, when Lamarck was) sixty-five 

 years of age. A partial translation of this work was 

 made by A. S. Packard and published in 1901. A com- 

 plete translation was made later by Hugh Elliot and was 

 published in 1914. It is to these translations we must go 

 for an understanding of the theory. At this point it may 

 be noted that neither translator clearly understood the 

 theory he was translating. In their comments, both 

 translators make statements which are contradicted by 

 the texts which they translated. When the translators 

 themselves misconstrue what they translate, it is not sur- 

 prising that others should do the same. 



About thirty years ago many cases of supposed in- 

 heritance of mutilations were advanced as evidence of 

 the truth of Lamarck's theory. This was attacked suc- 

 cessfully by August \Yeismann, who cut off the tails of 

 mice for many generations in succession and found that 

 tails grew just the same as before. This was looked 

 upon as a full refutation of Lamarck's theory, and a 

 great many persons so consider it at the present time. 



