INSTINCT 219 



believe that these several changes could thus have 

 been brought about by chance. 



Among some fishes it is said that the males, Arius 

 for example, carry the eggs in their mouth till they 

 are hatched. How could this instinct have originated 

 by natural selection? Why does not the male swal- 

 low the eggs as food instead of carrying them till they 

 hatch? 



In another fish, Aspredo, the eggs are attached to 

 various parts of the body by slender stalks. The eggs 

 of sharks have two tendrils at each end by means of 

 which they can attach themselves to objects and thus 

 be better protected. 



The male sea-horse carries the eggs in a pouch on 

 the under surface of the body till they are hatched. 

 The pouch in this case is pectoral, while the pouch of 

 the pipe-fish, which serves a similar purpose, is 

 under its tail. As to how these pouches could have 

 been evolved, together with the combined instincts of 

 the males and females which cause them to use the 

 pouches, is beyond my comprehension. It is indeed 

 easy to say that they were evolved gradually by natu- 

 ral selection, but the evidence to support this asser- 

 tion seems to me extremely insufficient. 



The instincts of animals with regard to depositing 

 their eggs in the most suitable places, the methods of 

 protecting their eggs, and the care of the young are 

 numerous and wonderful. 



It is a general law that the number of eggs pro- 

 duced by an animal is in proportion to the risks to 

 which they are subjected. Most fishes produce thou- 

 sands of eggs, but they are eaten in large quantities by 

 animals; also the young are destroyed in large num- 

 bers, so that if there were but few eggs the chances 

 for producing mature fishes would be greatly de- 



