278 T. H. MORGAN AND C. R. STOCKARD. 



The eggs in the latter solution are also plasmolized. In all three 

 solutions the eggs died after about fifty hours as abnormal gas- 

 trulae. 



Eggs in 5 per cent, glucose in one of the experiments, formed 

 abnormal gastrulae, which closely resembled those described 

 above in the 10 per cent, cane sugar, but in other experiments 

 only a few eggs attempted gastrulation, and the majority died 

 while in late segmentation stages. In the 5.5, 5.8 and 6 per 

 cent, solutions late segmentation was reached, but all eggs were 

 badly plasmolized with the animal pole flattened. Eggs in 

 a 6.5 per cent, solution died in much the same condition, 

 though plasmolysis occurred earlier in this solution. 



Eggs underwent only a few divisions after being subjected to 

 the 10 per cent, glucose solution, the effect was much the same 

 as that of the 20 per cent, cane sugar. 



In the 15 per cent, glucose the eggs were readily killed, the 

 blastomeres being ruptured after only one or two divisions, or 

 within about one hour after being subjected to the solution. 

 This serves to convey some idea of how quickly these high os- 

 motic pressures produce an effect. 



Laevulose solutions of 2, 3, 5, 5.5, 6, 6.5, 8 and 10 per cent, 

 were used. The general effects of such solutions were almost 

 identical with those described for the same percentage solutions 

 of glucose, showing that the actions were in the main part due 

 alone to their osmotic pressures, and not to any difference in 

 chemical action which the sugars might have exerted. One 

 would not expect the chemical action of these sugars to be 

 marked even if it was at all perceptible. 



A consideration of the responses of frog's eggs to sugars 

 would seem to indicate that the more violent action on Fundulus 

 eggs of fresh-water solutions of cane sugar when compared with 

 sea-water solutions is not due to the sugar in the fresh water hav- 

 ing become inverted. It will be recalled that Fundulus eggs are 

 more susceptible to the same percentage solution of a salt in 

 fresh water than in sea water. These facts together with the case 

 before mentioned of the augmented effect produced when sugar 

 is added to a weak solution of a salt in fresh water, even though 

 the pressure of the solution is below that of sea water, go to 



