318 H. H. NEWMAN. 



3. The position of the anal fin of the female is such that it sup- 

 ports the weight of both fish, the distal end of the fin being in 

 contact with the bottom which under natural conditions is usu- 

 ally composed of soft mud. Since this fin receives the vibratory 

 movement of the body it necessarily stirs up a considerable 

 amount of mud and also makes a shallow depression. The eggs, 

 as soon as they are extruded, fall to the bottom and either settle 

 in the small hole or are at least partially concealed by the settling 

 mud. That some such protection is necessary is shown by the 

 fact that the fish themselves are very fond of their own eggs, de- 

 vouring them eagerly when they can be seen. This curious 

 type of cannibalism was observed repeatedly in aquaria where the 

 bottom was free from mud. The females were the chief offenders 

 in this respect although young males occasionally devoured the 

 freshly extruded eggs. It was a very common sight to see other 

 females rush up and seize the eggs as soon as they were ex- 

 truded. Frequently, however, females were observed to turn and 

 devour their own eggs. This destruction of eggs probably occurs 

 only to a very limited extent under normal conditions for the 

 reasons cited above. 



Co2irtship, Rivalry and Display. 



As might be expected, the male takes the more active and ag- 

 gressive part in courtship but the female frequently displays her- 

 self in such a way and assumes such postures as are calculated to 

 attract the male. Females laden with very ripe eggs frequently 

 display themselves by turning on their sides near the bottom, 

 and spurning the latter with their tails, thus causing their silvery 

 white bellies to flash in the light. This, I noticed, seldom failed 

 to attract the males if there were any of the latter about. This 

 curious flashing movement is by no means restricted to the 

 females of this species, but was observed occasionally in the males 

 of the same species, in both sexes of FuHdulus majalis, and in 

 several other marine species. It was, however, especially notice- 

 able in actively spawning females and seems to be of undoubted 

 service in attracting males. 



When both sexes are at the height of their sexual activity 

 there is little that could be termed courtship. The females are 



