5 

 were ronresented. There v/ere mature females of both soecies 

 that deDOsited their eg'-2 thr next morninr at tie re.eular 

 Deriod; Stofr.gtoca rugcsa has the same time for dehiscence 

 as StgmpLOca apicata. Only tho egps of ihe latttr sDecies 

 develo ed; there being; no jialea of Stpr-otoca ruggsa. The 

 next day when the lwo soecies wer.^ in Ihe sa;ne dish, and both 

 discharged their egps , only the eggs of Stgrr-otoca rijgosa. 

 segmented and develced. In this case there were no mature 

 males of Stpmptpca apicata. These facts aroused my interest 

 and on several later occasions I ola^a the two species to- 

 gether with the intention of vetoing them to interbreed, 

 but did not succeed and therefore I am led to the conclusion 

 that, they will :;ct cross even though they are soecies of the 

 same genus. To my icnowledge no other exDoriments have been 

 made in attemoting to cross different s.:ecies of this group 

 of animals, and I did not have the onrcr. unity to try v/ith 

 any other s^'ccies than the above named after my attention 

 had been called to the fact that they did not/cross when ac- 

 cidentaly placed in a dish together, 



POLAR BODIES. 



Soon after the egg is denosited tl.e first pclor body 



