364 



Time. 



9.30 p. M., July 4. 

 10.30 p.m., July-1. 

 10.45 p. M., July 4. 

 10.50 p.m., July 4. 

 11.00 p. M., July 4. 

 11.10 p. M., July 4. 

 11.15 p. M., Julj' 4. 

 11.30 p. M., July 4. 

 11.55 p. M., July 4. 



T.\BLE 4. 



T.\UIOGL.\BHrS 



X 



T.iUTOGL.\BRUS. 



Fertilized. 

 Two cells. 

 Begin. 4 cells. 

 Wei) along in 4 cells. 

 Close of 4 cells. 

 Well begun on 8 cells. 

 Well along in 8 cells. 

 Begin. 16 cells. 

 16+cells. 



TAUIOGLVBHrS 



X 



FrNDuirs. 



Fertilized. 

 Two cells. 

 Close of 2 cells. 

 Begin. 4 cells. 

 Well along in 4 cells 

 Close of 4 cells. 

 Begin. 8 cells. 

 Close of 8 cells. 

 16-rcells. 



FunduTus heteroclitus, female, 



X 

 Tautoga onitis, male. 

 The percentage of eggs fertilized in the three experiments made was as 

 follows : 



Experiment 104 66 per cent. 



108 40 " " 



506 26 " " 



It is not probable that v.ith perfectly fresh milt the percentage would 

 be higher. I have observed, the sex products of both sexes in this species 

 materiall3" deteriorate upon confinement of the fish, even for a short time. 

 In experiment 506 good eggs wt^re used and perfectly fresh milt in abun- 

 dance was used. Practically all of the fertilized eggs are normally impreg- 

 nated. In experiment 506 every impregnated egg was normal. 



The development proceeds in the same manner as in the cross between 

 Fundulus and Tautoglabrus. Most of the e,ggs form a definite embryonic 

 rim and an apparently normal embryonic shield, but even though they 

 may .go to the closure of the blastopore, the embryo is always much too 

 short, never exceeding one-half the normal length. They are mostly shorter 

 than this, a mere thickened mass of cells developed in the embryonic shield. 

 In some cases the blastopore is practically closed, surrounded by a broad 

 embrvonie rim with the embrvonic 'Shield devoid of any em1>ryo. 



