Oral Gestation in the Gaff-Topsail Catfish, Felichthys Felis. 31 



ovaries. A number of these females were brought to the laboratory 

 in a live-car and kept in the turtle pound. Four days later the largest 

 of these was spawned artificially and gave up 68 grown eggs. 



In 1910, the first eggs were taken May 21, before my arrival. These 

 were few in number and low in vitality, whether because they were 

 naturally infertile or because they had not been fertilized could not 

 be determined. On May 25 we were fortunate in getting males with 

 eggs in early invagination stages. These were probably 3 to 5 days old. 

 On the following day more eggs of about the same stage were taken. 



In 1911, as noted elsewhere, two trips were made to Beaufort for 

 gaff-topsails. Having always been too late for early stages hereto- 

 fore, I went too soon this year. The first seining was done May 13 and 

 40 or 50 huge females were taken, but from none of them could eggs 

 be obtained. A large number of males was also caught but not one 

 had the depressed hyoid region indicative of the breeding season. 

 On May 15 a number of large females were obtained but none would 

 give up eggs. The males, however, of this day's catch had enlarged 

 oral cavities ready to receive eggs. None of these females had genital 

 orifices markedly reddened. This spring was a late cold one and had 

 evidently delayed the spawning beyond the normal time. 



My second trip in 1911 gave me a seining on May 25. From this 

 were obtained the youngest eggs ever gotten in this research eggs 

 with the invaginating edge of the blastoderm placed equatorially. 

 Here again I was too late for segmentation stages, the eggs having 

 been laid in my absence. However, they could hardly have been more 

 than 3 days old. 



The breeding season is plainly determined by the stage of ripeness 

 of the eggs and this is pretty definitely fixed by the temperature. 

 With a warm spring, egg-laying comes earlier, with a cold one later; 

 but the evidence seems to be that once the laying begins it is quickly 

 concluded. Normally this breeding season, as indicated by the data 

 above given, begins about May 18-20, and rarely extends over 10 

 days, probably being concluded in even less tune. This is plainly 

 evidenced by the difficulty in finding early stages, and further by the 

 fact that the majority of eggs taken in any season at any time are all 

 about the same stage. 



There must now, however, be given some data which contrasts 

 markedly with the foregoing. On July 21, 1910, there were brought 

 to me, by fishermen in Newport River, 2 male catfish with eggs and 

 larvae in then* mouths. The 5 larvae had their yolk-sacs four-fifths 

 closed over by the body-walls and were able to swim freely and actively. 



The 28 eggs had on them embryos which were just beginning to 

 show dark stippling on the dorsal parts, and were plainly from two 

 to three weeks younger than the larvae above described. This is a 

 remarkable case. The eggs were of a late laying. With this case 



