33 8 H. H. NEWMAN. 



to seek the open. The ruling male always approached these 

 females, which were ready to spawn, judging by their distended 

 abdomens, with so much fierceness and speed that they were 

 forced to retreat. Occasionally this male succeeded in cornering 

 a female in one of the angles of the aquarium either at the bottom 

 or at the sides, and spawned with her. The method of spawn- 

 ing is not unlike that observed in Fundulus licteroclitus. The 

 male holds the female just forward of her caudal fin, using chiefly 

 his very large, strong dorsal fin for this purpose. He lies slightly 

 on the back of the female, but mainly side by side with her. The 

 anal and ventral fins are used to hold the female up against the 

 clasping dorsal, but these fins do not, so 'far as I was able to 

 observe, clasp so firmly as in Funduliis. The approximation of 

 sexual openings is not nearly so close as in the last-named species 

 and hence there is probably less surety of successful fecundation. 

 The eggs and sperm are, however extruded in such close proxi- 

 mity that the chances of failure are comparatively slight. While 

 clasped by the male the female .vibrated the body as described 

 for Fundulus but more rapidly. In fact the whole spawning act 

 is of such short duration that it is extremely difficult to see 

 exactly what takes place. One has to make repeated observa- 

 tions, watching each detail of the process and even then some 

 details elude ones most careful scrutiny. 



July 22.- -Two days later the ruling male still continued to 

 rule although challenged frequently by the other male, now 

 almost equally brilliant. The encounters between these two bel- 

 ligerents was very interesting, reminding one of nothing so much as 

 an encounter between two game cocks. They approach threaten- 

 ingly, every fin erected and body quivering for the fray. Then 

 they dash at one another, the ruling male being slightly more 

 aggressive. After an encounter, much more evenly waged than 

 on the former occasion, the rival male gives up temporarily and 

 retires to his corner. He is still full of fight, however, for in a 



o 



few moments he begins to make threatening demonstrations in 

 his corner, turning sudden summersaults and making quick, active 

 darts out and back. This behavior never fails to bring his oppo- 

 nent to the fray again. This sort of thing usually lasts until one 

 of the combatants-- always the lesser male grows weary and 



