The Evolution of Parental Care 37 



tion in the higher animals. 



We cannot of course follow step by step all the 

 stages in the evolution of the parental instincts and 

 feelings, but by a comparative survey of the animal 

 kingdom it is possible to construct, with some degree 

 of probability, the main outlines of this development. 

 Among the lower invertebrates the offspring have to 

 shift for themselves at their very first appearance 

 upon the stage of life. There are sometimes devices 

 such as brood pouches for the protection of the eggs 

 or young, but any active solicitude of parents for 

 their offspring does not appear until we reach the 

 higher invertebrate animals. This lack of parental 

 interest is well illustrated by the behavior of an am- 

 phipod crustacean, Amphithoe, which the writer 

 studied in some detail a few years ago. In this form 

 the eggs, and also the young for a few days after 

 being hatched, are carried in a brood pouch on the 

 under side of the body. When sufficiently agile the 

 young make their way out of the brood pouch and 

 swim away, the mother paying no more attention to 

 them than to any other animate object. Indeed the 

 carnivorous habits of this species make it more or 

 less dangerous for the young to tarry long in the 

 vicinity of their parent. Several times I have caught 

 the young in a fine pair of forceps and offered them 

 to the mother, who ate them without the least com- 

 punction. It is only in a grossly material sense, 

 therefore, that Amphithoe can be said to be fond of 

 its offspring. 



