92 Seal — Breeding Habits of Viviparous Fishes. 



The only recorded observation of the breeding habits of Gam- 

 busia is to be found in the proceedings of the XL S. National 

 Museum for 1885, credited by the late Prof. John A. Ryder to 

 A. A. Duly an employee of the Museum. This account appears 

 also as a footnote to Bulletin No. 47, U. S. Nat. Mus., Fishes 

 of North America. 



Having observed the act of coition and of the extrusion of the 

 young of both of these species a great many times every year, 

 beginning with 1906, I am satisfied that Mr. Duly's account of 

 it is, in many respects at least, incorrect. First, he says, " In 

 coitus the male's head is turned in the direction of the tail of 

 the female, the prolonged anal fin seeming to be thrust into the 

 external opening of the ovarian duct or genital pore of the 

 female, which lies just in advance of the anal fin." I have 

 never witnessed anything like that, nor is it an analogical 

 method. On the contrary the male follows incessantly and 

 warily after the female, on the left side and to the rear, the 

 female frequently turning and making savage dives at him 

 causing him to turn and flee, but to return immediately and 

 follow, watching for a moment when her attention will be dis- 

 tracted when he will make a sudden dash, sometimes .succeeding 

 in inserting the intromittent organ into the genital pore, but 

 oftener, apparently, missing because of a quick turn of the 

 female from which he flees in apparent terror. The contact is 

 so sudden and brief that it required many observations to verify 

 it. In these movements the male organ is thrust forward and 

 to the right toward the female. In small jars the males are 

 frequently killed, especially when the female is full sized, or if 

 there are two or three females to one male. It has been noted 

 that when catching them there appears to be a great preponder- 

 ance of females, but that might be due to the fact that as the 

 males are much smaller than the females they could more easily 

 escape through the meshes of a net. 



In the aquarium the males are continually engaged in a pur- 

 suit of the females while the females are apparently adverse to 

 sexual dalliance and at all times unwilling participators and 

 quick to resent the advances of the males. I have never wit- 

 nessed anything to indicate a reciprocity of desire in coitus it 

 being always a chance touch and go on the part of the males. 

 There is never more than the one male following a female. If 

 others approach, the male turns and drives them off. 



