The Biology of the Crocodilia 17 



ful head, and during the breeding season especially 

 is more brilliantly colored." 



It is a very common belief, even among those 

 who should be most familiar with their habits, 

 that the growth of the alligator is remarkably slow, 

 so that a large specimen may be described by the 

 exhibitor as more than a century old. The same 

 dealer in alligators quoted above says upon this 

 subject: "You can figure about two inches a year 

 to their growth." He also says: "We judge that 

 an alligator about twenty-five to thirty years old 

 will breed." Even scientific writers of reputation 

 have not been free from this error in their writings. 

 That the alligator may live to an extreme age, as 

 seems to be true of some of the tortoises, is quite pos- 

 sible, and it is probable that after reaching a length 

 of twelve or fifteen feet the growth is very slow. 



In captivity, when kept in warm water and 

 other favorable conditions, the alligator will grow, 

 according to measurements taken at the New York 

 Zoological Park, at the rate of about one foot a 

 year, for about the first ten years. Under unfavor- 

 able conditions the growth may be exceedingly 

 slow. Under favorable conditions in nature the 

 rate of growth may exceed that given above. 



Instead of requiring twenty-five to thirty years 

 to reach sexual maturity, as quoted above, it is 

 likely that the female may lay eggs at five to ten 

 years, though such a fact is difficult to determine 

 of animals in their native haunts. 



