NOGUCHI 



PLATE 30 







1 to 4. Eggs of Arbacia punctulata. 1 , Normal. 2 to 4, Different stages of 

 Ovolysis caused by I per cent Cobra venom in sea-water. 



5 to 8. Eggs of Lepidonatus squamatus. 5, Normal. 6 and 7, Different stages 

 of Ovolysis caused by I per cent Cobra and 2 per cent Crotalus venom, 

 showing no real Ovolysis, but peculiar Retraction of Deutoplasm. 



9 to 11. Pluteus stage of Arbacia punctulata. 9, Normal, active pluteus. 10, Plu- 

 teus under the effect of 2 per cent Cobra venom. 1 1 , Disintegration 

 under the effect of same venom. 



(Drawings by Noguchi. > 



