194 EMBRYOLOGY IN THE SEVENTEENTH [pt. ii 



others as i to 15. In the first 3 years of extra-uterine life his growth 

 will be from 164 to 281 and in the succeeding 22 years from 281 to 

 384, and the growth of the first month to the last will be as 300,000 

 to ^% or 136,800,000 to 28, or 4,885,717 to i. The whole growth of 

 man will consequently be as 108,000,000 to i." 



In spite of the rather unfamiliar language in which these facts are 

 described, and the theory of the growth of the heart which Haller 

 subsequently put forth to explain them, they remain fundamental 

 to embryology. Their quantitative tone is indeed remarkably modern. 

 In my opinion, when all the voluminous writings of Haller are care- 

 fully searched through, nothing more progressive and valuable than 

 these figures can be found. Haller and Hamberger stand thus 

 between Leonardo on the one hand and Minot and Brody on the 

 other. That they stood so much alone is only another indication of 

 the extraordinary reluctance with which the men of past generations 

 assented to the truth contained in Robert Mayer's immortal words, 

 "Eine einzige Zahl hat mehr wahren und bleibenden Wert als eine 

 kostbare Bibliothek von Hypothesen". 



Of development as a whole, Haller spoke thus, " In the body of the 

 animal therefore, no part is made before any other part, but all are 

 formed at the same time. If certain authors have said that the animal 

 begins to be formed by the backbone, by the brain, or by the heart, if 

 Galen taught that it was the liver which was first formed, if others have 

 said that it was the belly and the head, or the spinal marrow with the 

 brain, adding that these parts make others in turn, I think that all these 

 authors only meant that the heart and the brain or whatever organ 

 it was, were visible when none of the other parts yet were, and that 

 certain parts of the embryonic body are well enough developed in the 

 first few days to be seen while others are not so until the latter part of 

 development; and others again not till after birth, such as the beard 

 in man, the antlers in the stag, the breasts and the second set of teeth. 

 If Harvey thought he descried an epigenetic development, it was 

 because he saw first a little cloud, then the rudiments of the head, with 

 the eyes bigger than the whole body, and little by little the viscera 

 being formed. If one compares his description with mine, one will see 

 that his description of the development of the deer corresponds 

 exactly with mine of the development of the chick. If, more than 

 twenty years ago, before I had made many observations upon eggs 

 and the females of quadrupeds I employed this reasoning to prove 



