THE ORIGIN OF SPECIES. 55 



•of familiar things. The most remarkable additions 

 to previous knowledge regarding the world of living 

 things were those made by the study of the de- 

 velopment of the young animal. We must for the 

 present defer any detailed account of this branch of 

 zoology, which shortly attained the rank of a separate 

 branch of science ; but something may here be stated 

 regarding the general laws of development which have 

 been formulated as a result of the facts observed. 

 The development of a young animal, or plant, in its 

 passage from its early and simple to its final and 

 complex form, presents, as has been already stated (p. 

 27), a series of stages which afford a striking parallel 

 to the artificial series given by a classification such as 

 is generally adopted by zoologists, in which the various 

 types are so arranged as to exhibit a gradual pro- 

 gression towards the most perfect and complex form. 

 That the character of the immediate parent is, in the 

 course of an individual's development, the last to assert 

 itself, we know from the facts of common observation. 

 Thus, the " family likeness " comes out late in life 

 in human faces which, when young, seemed to bear 

 no resemblance to the parents. Thus, also, you may 

 often trace in the fur of the blackest kitten of the 

 black cat, when it is only a few days old, indications 

 of the stripes which were the characteristic of its 

 striped ancestor. Similarly, foals show stripes which 

 indicate the descent of the horse from a striped zebra- 

 like ancestor. As the kitten or foal grows older, 

 these stripes disappear ; in brief, the character of the 



