367 
TABLE 7. 
eae = tiene ET pie 
TIME. | FunpuLus X FUNDULUS. FUuNDuLus X STEPNOSTOMUS. 
} 
| 
| 
10.50 a. M., July 11. | Fertilization. Fertilization. 
11.37 a. M., July 11. Begin. 2 cells. Begin. 2 cells. 
11.55 a. M., July 11. | Compl. 2 cells. Compl. 2 cells. 
12.05 p. M., July 11. Begin. 4 cells. Begin. 4 cells. 
12.35 p. M., July 11. Compl. 4 cells. Compl. 4 cells. 
12.40 p. M., July 11. Begin. 8 cells. Begin. 8 cells. 
1.00 p. m., July 11. Compl. 8 cells. Compl. 8 cells. 
1.05 Pp. M., July 11. Begin. 16 cells. Begin. 16 cells. 
11.00 vp. M., July 12. Late cleavage. Late cleavage. 
1.25 p. M., July 12. Well developed germ ring and | Some begin. of germ ring. 
shield 4 over. 
3.30 p. M., July 12. ; over yolk. 4 over yolk. 
7.20 Pp. M., July 12. 2 over yolk. 3 over yolk. 
8.00 a. M., July 13. Blast. closed. Most nearly closed. Embryos 
too short. 
1.00 Pp. M., July 13. No further along. 
Fundulus heteroclitus, female, 
x 
Hupomotis gibbosus, male. 
This cross was attempted six times, only three of which were success- 
ful. The number of eggs impregnated each time was very small. I do 
not think this was due to the condition of the milt, because an abundance of 
apparently good milt was used. The dry method was used and the eggs 
kept in fresh water. P 
Experiment 7.. : _. Less than 1 per cent. 
ai SMAI ET RRR SENS Sc acne ee Avy waht oes 
Maes cass yeeepevsieer ten veierers) = 5. Rr oi dees 
“ ‘ 
bo 
The eggs were followed to about one-third to one-half over the yolk 
when they stopped development. An embryonic ring and shield were deyel- 
oped, but the protoplasm did not look normal even in earlier stages of gas- 
trulation showing a relatively opaque appearance compared with normal 
eggs. 
The reciprocal of this cross was not attempted owing to a failure to get 
ripe eggs of the sunfish. 
