GERMINAL LOCALIZATION IN THE EGG OF CEREBRATULUS. 



9 



A portion of cytoplasm was cut ofif from the egg immediately 

 after the second polocyte was formed (Fig. 4. A). This w^as a 

 repetition of the experiments described in my previous paper, 

 and a similar result was reached. Ten pilidia were produced 

 from the fragments. Two cases' may be w^orth mentioning here ; 

 in one the cut passed through the equator (Fig. 4. b, B) and 

 in the other the section was near the animal pole (Fig. 4 c, C)"*, 

 yet in comparing the resulting larvœ the gut is found to be 

 more defective in the former than in the latter. This undoubt- 

 edly shoAvs that by this stage there is a great variation in the 

 extension of the entodermic stuff in the egg. 



Series D. Removal Experiment performed at the Metaphase 



of the First Maturation Mitosis ; both the Nucleated 



and the Enucleated Fragments were Fertilized. 



Eggs were cut 

 along various hori- 

 zontal planes at the 

 metaphase of the first 

 maturation mitosis and 

 both the fragments 

 were fertilized. Thus 

 form a single egg both 

 A, diagram showing the operation in Series amphikaryotic and 

 D ; B, diagram showing the planes of cuts a, arrhenokaryotic (me- 



h, c, d, e and f. ...,.,. 



rogonic) pilidia were 



obtained. This experiment has a decided advantage over Series 



A and B, since by this method the development of the vegital 



3 Fig. 4 C was drawn greatly compressed. 



