28 HARRIETT M. ALLYN. 



opportunity to make only the most hasty examination. It might 

 well repay further work. The method employed was to open up 

 the ovaries in solutions other than sea-water: The female was 

 rinsed one minute in distilled water, to wash off the sea-water, 

 then dried on filter paper sufficiently to remove external moisture. 

 The sex segments were then cut off and placed in the desired 

 solutions, where the eggs were teased out. The results were as 

 follows : 



A . Body Fluid. When no solution was supplied and the eggs 

 were merely allowed to come out of the ovary into a drop of body 

 fluid (which is plentiful in the sex segments outside the ovary 

 tubes), the germinal vesicle broke down, its contents migrated 

 to the animal pole, the spindle formed, and the membrane as- 

 sumed its normal relation to the egg. In short the whole process 

 appeared to be normal. Since the body fluid can produce these 

 changes it must be supposed either that the ovarian wall is 

 impermeable to the body fluid, or that an oxygen supply greater 

 than that within the ovary must be furnished in order to induce 

 the changes. To test this last suggestion sex segments were 

 opened up in water which had been de-aerated by boiling. 



B. De-aerated Sea-water .In this case the female had not 

 been dried as formerly, since sea-water was to be used. Eggs 

 taken from the ovary in de-aerated sea-water behaved normally 

 in all respects. It is of course possible that sufficient oxygen 

 was carried in with the eggs to have an effect on the processes, 

 but it scarcely seems probable that much increase in oxygen 

 supply over that present in the ovaries was furnished the eggs in 

 the experiment. Therefore, it would appear that the reason 

 that the eggs do not go through the first stage in the ovaries is 

 that the wall of the ovary is semi-permeable to the body fluid, 

 not allowing a sufficient amount of it to enter to cause the eggs to 

 go through the changes described. 



C. Salt Solutions. In order to determine whether any of 'the 

 salts in the sea-water were necessary factors in the determination 

 of these first developmental changes, solutions of various salts 

 were used, n/2 sodium chloride, n/2 potassium chloride, n/2 

 calcium chloride, and n/2 magnesium chloride. The n/2 sodium 

 chloride and n/2 potassium chloride led to the break-down of the 



