No. 447-] 



HA MINE A SOLITARIA SAY 



eel pond in bottles closed with several thicknesses of cheese 

 cloth. In placing the embryos in their natural environment, it 

 was hoped that it would be possible to determine tlie chan.^es 

 taking place between the embryo and the adult. Althou-h 

 repeated experiments were made in various parts of the eel i)()ncl, 

 no satisfactory results were obtained and I am unable to stale 

 how the transition from the embryo to the adult takes ])!ace. 



During the summer of 1899 a number of pressure experi- 

 ments were tried for the purpose of determining the effect on 

 segmentation and the subsequent history of the embryo. The 

 fact that the eggs are surrounded by a great mass of albuminous 



material made it easy to apply light pressure. A small number 

 of eggs were placed on a slide and covered by a second slide, 

 the amount of pressure was regulated by passing a small rubber 

 band around the slides. The eggs were taken in the one celled 

 stage after the polar bodies had formed ; they were leti under 

 pressure two hours and the changes which took place during tlie 

 period were carefully noted. I took pains to see that all ()f the 



pressure was removed the eggs were i.laeed in the ;u|uanuni in 



