126 H. H. NEWMAN. 



The male and female pronuclei are in contact and are contained 

 within the main body of the formative protoplasm and are 

 closely similar in size and in the condition of their chromatin, 

 which is peculiar in that each chromosome appears to be a 

 small vesicle, connected with others by means of linin fibers. 

 A large plasmosome is present in each pronucleus. The cyto- 

 plasm does not show so clear a demarkation between formative 

 and deutoplasmic zones as is usually seen in the maturation 

 stages, but this is probably due to the fact that the plane of 

 section is equatorial and therefore unfavorable for showing polar 

 differentiation of any sort. 



This account of a single case of fertilization might be con- 

 sidered a somewhat meager basis for an account of so important 

 a process, but it is the best that can be offered at present. It 

 is my conviction that the discovery of even one such stage is a 

 fortunate circumstance, in view of the fact that we are dealing 

 with wild animals captured at night and not operated on until 

 the following morning at the earliest. Only rarely is it possible 

 to obtain the females so soon after capture as this. The uterus 

 associated with the ovary in which this fertilized egg was found 

 was somewhat swollen and congested and was supposed to 

 contain an early blastodermic vesicle, but on examination was 

 found to be non-pregnant. No other ova were found in the 

 fallopian tube, either proximal or distal to the cite of the one 

 under discussion. There is a single medium-sized corpus luteum. 

 These facts demonstrate that only one ovum is given off and 

 fertilized at one time, and add confirmation to the contention 

 that during the early stages of embryonic development in the 

 armadillo the conditions are those of a single fertilized egg and 

 a single blastodermic vesicle and that the separation into four 

 embryonic rudiments is a process of asexual multiplication, 

 whose visible manifestation comes comparatively late in the 

 development of the blastodermic vesicle. 



SUMMARY AND CONCLUSIONS. 



i . A study of the ovogenesis of the armadillo reveals nothing 

 unique except that the cytoplasmic polarity of the mature 

 ovocyte and its genesis is practically identical with that of the 



