23 



Tlius tlie latter half of the embryonal time seems to l)e employed in developing the specific characters, while drobably, 

 in reality, all the Cetacean characters and the inner organs standing in corelation with them, continue steadily to be 

 developed and perfected, so as to ensure the air-breathing, warm-blooded young mammal an independent existence in the 

 cold, rough element. 



The course of developenient shown l>y tiie above-described copious embryonic material, from the embryo of 2V2 

 centim.'s length to the full-grown foetus, makes the deduction of a few general conclusions justifiable. As soon as the ordinary 

 embryonal mammal-form is attained, the characters of the order and of the sub-order appear, and assert themselves. These 

 are closely followed by those of the family, genus and species. What is remarkable in this is, that distinctive generic and 

 specific marks make so early an appearance, or. in other words, that the embryo's developement aims directly at the special 

 genus and species. The embryo seeks, by the most direct way, if I may use the expression, to attain to the 

 likeness of its parents, or, in other words, to the specific form. This also shows how cautiously one must advance 

 if direct phylogenic conclusions are to be drawn from embryological phenomena. 



