Ij6 ARTHUR W. GREELEY. 



all the solutions used, whether they exert a chemical or an 

 osmotic effect upon the egg. But, at the same time, with lower 

 temperatures and longer periods of exposure to the solution, a 

 larger percentage of larvae are formed than at the temperature of 

 the room. 



2. An increase of temperature to 27 C. liquefies the pro- 

 toplasm of the Asterias egg, and produces a fragmentation of the 

 nucleus. At 30 C. it was found impossible to produce artificial 

 parthenogenesis in Asterias or Arbacia with any of the solutions 

 used. 



