114 SEX-LORE 



already among the fishes, and it takes on some 

 curious forms. It is rare for the female to play an 

 active part; in fact, quite unlike the habit of the 

 higher animals, the male is the guardian of the young, 

 though there are exceptions to the rule. It is a re- 

 markable fact that while male fishes will devour the 

 eggs of any other species, they will not touch those 

 of their own species. Instinct acts here with aston- 

 ishing certainty. In some species, as Sutherland 

 has described, " the flat belly of the female becomes 

 at breeding-time quite soft like putty, so that when 

 the eggs have been fertilized by the male, by rolling 

 herself upon them she makes them stick to her. 

 There they are carried until they are hatched." 

 This method is so successful in protecting the eggs 

 that less than 2,000 are sufficient to keep up the 

 number of the race, though the nearest species, which 

 have no such habit, require about 60,000. In other 

 cases, the female carries her eggs in a pouch; they 

 are extruded into this pouch, and are hatched there 

 in comparative safety. 



It is more usual, however, for the male to under- 

 take the duty of caring for the young. This is done 

 in many ways. Some males are furnished with 

 pouches to carry the eggs until they are hatched. 

 Others, again, attach the eggs to the underside of 

 the body, which is soft and adhesive. Stranger still 

 are the cases in which the male carries the eggs in 

 his mouth until they are hatched, and sometimes 

 even keeps the young there until they are of con- 

 siderable size. This method is so safe that very 

 few eggs are needed to keep up the number of the 

 race. A slight variation is exhibited by the Para- 



