SAVIGNY 83 



is here applied to single organ-systems, but in later years 

 Serres applied it to whole organisations also, saying that the 

 lower Invertebrates were permanent embryos of the higher. 



In the paper of 1834, already referred to, Serres pushed his 

 speculations further and attempted to establish the unity of 

 type of all animals, Vertebrates and Invertebrates alike 

 a favourite pastime of the transcendentalists. It is incontest- 

 able, he admits, that adult Invertebrates are quite, different 

 in structure from adult Vertebrates, " but if one regards them 

 as what I take them to be, namely, permanent embryos, and if 

 one compares their organisation with the embryogeny of 

 Vertebrates, one sees the differences disappear, and from their 

 analogies arise a crowd of unsuspected resemblances (Joe. cit., 

 p. 247). 



The last point of Serres' doctrine which calls for remark 

 is his interpretation of abnormalities as being often com- 

 parable to grades of structure permanent in the lower 

 animals. Thus the double aorta which may occur as an 

 abnormality in man is the normal and permanent state 

 in reptiles. This idea, of course, he got from Etienne 

 Geoffroy St Hilaire. It is further developed in his 

 ' T/i^orie des formations et des deformations organiques 

 applique e a I 'anatomic comparee des monstruosites (1832), 

 and in his final large memoir of 1860 (see below, 

 p. 205). 



In 1816 appeared a fine piece of work by J. C. Savigny 

 on the homologies of the appendages in Articulates. The 

 standpoint was that of pure morphology. " I am con- 

 vinced," he wrote, " that when a more complete examina- 

 tion has been made of the mouth of insects, properly so 

 called, that is to say, having six legs and two antennae, it 

 will be found that whatever form it affects it is always 

 essentially composed of the same elements. . . . The organ 

 remains the same, only the function is modified or changed 

 such is Nature's constant plan." 1 In this the influence 

 of Geoffroy can be traced ; but the work was very free from 

 the exaggerations of the transcendentalists, and many of 

 Savigny's homologies are accepted even to-day. The 

 first memoir dealt with the mouth-parts of insects ; the 



1 Mcmoires sur les Aniuianx sans Vertcbres, Part I., p. 10, Paris, 1816. 



