8 THE EVOLUTION OF MAN. 



place of the Latin B or D, a Greek B or A is often found. 

 Here, therefore, the text of the biogenetic first principle is 

 vitiated, while in the former case it was epitomized. This 

 gives more importance to the fact that, notwithstanding 

 this, the sequence remains the same, so that we are enabled 

 to recognize its original order. 



Indeed, there is always a complete parallelism between the 

 two series of evolution. This is, however, vitiated by the 

 fact that in most cases many forms which formerly existed 

 and actually lived in the phylogenetic series are now wanting, 

 and have been lost from the ontogenetic series of evolution. 

 If the •parallelism between the two series were perfect, and 

 if this great fundamental law of the causal connection between 

 Ontogeny and Phylogeny, in the strict sense of the word, 

 had full and unconditional sway, we should only have to 

 ascertain, with the aid of microscope and scalpel, the series of 

 forms through which the fertilized human egg passes before 

 it attains its complete development. Such an examination 

 would at once give us a complete picture of the remarkable 

 series of forms through which the animal ancestors of the 

 human race have passed, from the beginning of organic 

 creation to the first appearance of man. But this repro- 

 duction of the Phylogeny in the Ontogeny is complete only 

 in rare instances, and seldom corresponds to the entire series 

 of the letters of the alphabet. In fact, in most cases the 

 epitome is very incomplete, and greatly altered and per- 

 verted by causes which we shall investigate hereafter. Hence 

 we are seldom able to determine directly, by means of its 

 Ontogeny, the different forms through which the ancestry of 

 each organism has passed ; on the contrary, we commonly 

 find, — and not less so in the Phylogeny of man, — a number 



