274 



THE EVOLUTION OF SEX. 



Geer describes how one of the insects infesting plants behaves 

 to her young brood exactly like a hen with her chickens ; and 

 Bonnet vividly describes a case where a mother spider, at the 

 mercy of an ant-lion, fought for her eggs at the sacrifice of her 

 own life. Some spiders, too, carry their young ; and some 

 crustaceans, like Gammarus, swim along with their young ones, 

 like a hen among her chickens. Some cuttlefishes take pains 

 in keeping their egg clusters clean and safe ; while even the 

 headless fresh-water mussel retains her young, when there is no 

 fish present to which they may attach themselves. In fishes, 



r A 



Egg-Clusters of a species of Cuttlefish.— From Von Hayek. 



It must be allowed that the care, if at all evident, is usually 

 paternal ; in amphibians, it is rare ; in reptiles, somewhat more 

 marked. In birds and mammals, however, parental care is 

 general, and unquestionably grows into love for offspring. 



§ 6. The Habits of the Cuckoo. — As animals exhibit the 

 analogues of the human virtues, it is not surprising to find 

 the occurrence of parallel vices. Those of much magnitude, 

 such as parental negligence or cruelty, are however rare, for 

 the conditions of life are too simple to admit of such developed 



