TO THE LOWER ANIMALS. 81 



time these thirty years. "Without question, the mode of 

 origin and the early stages of the development of man are 

 identical with those of the animals immediately below him 

 in the scale : without a doubt, in these respects, he is far 

 nearer the Apes, than the Apes are to the Dog. 



The Human ovum is about T | T of an inch in diameter, 

 and might be described in the same terms as that of the 

 Dog, so that I need only refer to the figure illustrative 

 (15 A.) of its structure. It leaves the organ in which it is 

 formed in a similar fashion and enters the organic cham- 

 ber prepared for its reception in the same way, the condi- 

 tions of its development being in all respects the same. 

 It has not yet been possible (and only by some rare chance 

 can it ever be possible) to study the human ovum in so 

 early a developmental stage as that of yelk division, but 

 there is every reason to conclude that the changes it un- 

 dergoes are identical with those exhibited by the ova of 

 other vertebrated animals ; for the formative materials of 

 which the rudimentary human body is composed, in the 

 earliest conditions in which it has been observed, are the 

 same as those of other animals. Some of these earliest 

 stages are figured below and, as will be seen, they are 

 strictly comparable to the very early states of the Dog ; 

 the marvellous correspondence between the two which is 

 kept up, even for some time, as development advances, 

 becoming apparent by the simple comparison of the fig- 

 ures with those on page 63. 



Indeed, it is very long before the body of the young 

 human being can be readily discriminated from that of 

 the young puppy ; but, at a tolerably early period, the 

 two become distinguishable by the different form of their 

 adjuncts, the yelk-sac and the allantois. The former, in 

 the Dog, becomes long and spindle-shaped, while in Man 

 it remains spherical : the latter, in the Dog, attains an ex- 

 4* 



