1 66 SECRETS OF EARTH AND SEA 



eggs which develop without fertilization by males — that 

 is to say, are " impaternate." In the case of the water-fleas 

 these are called "summer eggs," and after one or more 

 generations of such fatherless females a proportion of 

 males are produced which fertilize the females hatched 

 at the same period. The eggs so fertilized acquire a 

 thick shell and are called " winter eggs." They remain 

 dormant for some months and resist the injurious in- 

 fluences of winter cold, or, it may be, of drying up and 

 conversion of the pond-mud into dust, but hatch out when 

 warmer and wetter conditions return. 



This, however, is just what the adult crawling kind 

 of Rotifer can do in the full-grown state by drawing 

 up her body into the shape of a ball and exuding 

 a jelly-like or horny coat. So that she has no need 

 of " winter eggs," and the whole process of forming 

 them and of males to impregnate them has " dropped 

 out" of the life-history of this special kind of resist- 

 ant Rotifers. The minute insignificant males and the 

 eventual disappearance of males altogether in some races 

 is a subject which may well occupy the attention of 

 our human " suffragettes." That the males are minute 

 creatures, less than the thousandth part of the size of the 

 females, is a fact also ascertained in the case of some 

 curious marine worms (called Bonellia and Hamingia). 

 The only other instance of such degradation of the male 

 sex is in some of the barnacles (discovered by Darwin), in 

 which the big individuals are of double sex (hermaphrodite). 

 Adhering to the shells of these are found minute dot-like 

 11 supplemental males." It is to be observed that these 

 are instances where the inferiority of the male is an 

 obvious measurable fact. In the mammals, the group of 

 vertebrate animals to which man belongs, the male 

 possesses measurably greater activity and size than does 

 the female, and is provided with more powerful natural 



