C0PE1A 71 



The remaining five suckers were killed after 24 

 hours of isolation in the live-car. No whole eggs were 

 found in the alimentary canals of these fish, and only 

 small masses of oil and sand were present in the pos- 

 terior portions of the intestines. The absence of eggs 

 in the alimentary canals of these five fish, collected 

 while feeding with the other 15, considered with the 

 fact that the alimentary canals of the other 15 con- 

 tained an average of 500 eggs each, suggests the pos- 

 sible consumption of at least 500 log perch eggs every 

 24 hours by each sucker following the schools of log 

 perch. The actual destruction of eggs by each sucker 

 is probably greater, however, as the broken eggs re- 

 main uncounted. The percentage of the total num- 

 ber of eggs produced by the female log perch of these 

 schools, destroyed by the suckers was not ascertained. 

 Several female log perch taken at random yielded 

 about 100 mature eggs each, although the ovaries of 

 these fish contained large numbers of immature eggs. 

 While considering the destruction of the log 

 perch eggs by suckers it may be noted that the log 

 perch themselves crowd about spawning individuals 

 of their own species and devour the recently-laid eggs. 

 Ten male log perch collected with the suckers were 

 examined and from eight to 20 eggs were found in 

 the stomach of each one. 



M. M. Ellis, 

 G. C, Roe, 

 Boulder, Colorado. 



NOTES ON THE BREEDING AND INCU- 

 BATION PERIODS OF THE IOWA, 

 DARTER, ETHEOSTOMA IOWAE 

 JORDAN AND MEEK. 



While collecting embryological material during 

 the spring of 1917 the eggs of the Iowa Darter, 

 Eiheostoma iowae, were obtained, fertilized and car- 

 ried through the hatching period. 



