EFFECTS OF INJURY UPON SPERM. 239 



although egg sections from early preservations of the experi- 

 mental series show in some slides as many as 5 per cent, of the 

 maturing eggs with the alveoli of the cortical layer still wholly 

 or partially filled. In most cases an attached sperm cell may be 

 found outside the vitelline membrane. Since it is in an exposed 

 position, not protected by jelly as in other eggs, its absence may 

 be interpreted as due to its accidental removal after preservation. 

 I have not found fertilization cones in sections which show any 

 considerable amount of material still present in the cortical 

 alveoli. Maturation goes on in an apparently normal fashion 

 (Fig. i) though probably much slower than usual since the later 

 maturation stages of this type are not seen until the normal 

 maturation stages have been completed for some time. I have 

 found most of the principal maturation stages, from the breaking 

 down of the germinal vesicle to the formation of the vesicles of 

 the female nucleus, and, with the exception of the cortical layer, 

 they seem to be like the normal stages. The polar bodies either 

 come to lie imbedded in the cortical layer, or are pushed entirely 

 through it to the outside (Fig. 2). After the formation of the 

 second polar body the chromosomes, in the usual manner, rapidly 

 form a number of large chromosomal vesicles with the haploid 

 number of chromatic nucleoli. But no indication of the sperm 

 is to be seen within the egg. No trace of cytoplasmic radiations 

 is ever seen within the egg after the maturation phenomena are 

 completed and the sperm nucleus is not to be found unless the 

 remnants of the sperm cell are still attached to the outside of the 

 vitelline membrane. The chromosomal vesicles, not being able 

 to fuse with the sperm nucleus, may now behave in one of several 

 ways. They may scatter at random through the cytoplasm or 

 they may retain their position beneath the polar bodies, in which 

 case they usually form a more or less hazy, pcorly staining mass 

 of irregular shape. In a few cases I have found about a dozen 

 separate or partially fused vesicles containing in all about 26 

 chromatic nucleoli. At first I thought that this was a case in 

 which the sperm had entered. But the entire absence of cyto- 

 plasmic radiations, the irregular arrangement of the vesicles, 

 and the determination of approximately the haploid number of 

 vesicles indicates that we are dealing with a case of multiplica- 



