THE EMBKYOLOGY OF THE SOUL. 149 



The swimming tadpole has not only the structure, but 

 the habits of life, of a fish, and only acquires those 

 of a frog in its metamorphosis. 



It is different with man and all the other amniotes ; 

 their embryo is entirely withdrawn from the direct 

 influence of the outer world, and cut off from any 

 reciprocal action therewith, by enclosure in its pro- 

 tective membranes. Besides, the special care of the 

 young on the part of the amniotes gives their embryo 

 much more favourable conditions for the cenogenetic 

 abbreviation of the palingenetic evolution. There is, 

 in the first place, the excellent arrangement for the 

 nourishment of the embryo ; in the reptiles, birds, 

 and monotremes (the oviparous mammals) it is 

 effected by the great yellow nutritive yelk, which is 

 associated with the egg ; in the rest of the mammals 

 (the marsupials and placentals) it is effected by the 

 mother's blood, which is conducted to the foetus by 

 the blood vessels of the yelk-sac and the allantois. 

 In the case of the most highly developed placentals 

 this elaborate nutritive arrangement has reached the 

 highest degree of perfection by the construction of 

 a placenta ; hence in these classes the embryo is fully 

 developed before birth. But its soul remains during 

 all this time in a state of embryonic slumber, a state 

 of repose which Preyer has justly compared to the 

 hibernation of animals. We have a similar long 

 sleep in the chrysalis stage of those insects which 

 undergo a complete metamorphosis — butterflies, bees, 

 flies, beetles, and so forth. This sleep of the pupa, 

 during which the most important formations of 

 organs and tissues take place, is the more interesting 

 from the fact that the preceding condition of the free 

 larva (caterpillar, grub, or maggot) included a highly 



