TOO 



CHILD. 



the bands are broader than in Fig. 49. As yet, however, there 

 is no trace of the inter-proglottidal furrows upon the margins or 

 surfaces of the body, and indeed the grouping of the nuclei does 

 not extend into the peripheral parenchyma at all. 



1:1 1 







FIG. 50. 



Fig. 5 i shows a still later stage in the process of proglottid- 

 formation. The bands of nuclei are still broader and more dis- 

 tinctly marked in the middle region of the body, though the 

 nuclei are still more abundant in the lateral regions of the central 

 parenchyma. It is evident that the number of nuclei is increas- 

 ing. One marked advance in the development is noticeable here, 

 viz., the arrangement of the nuclei in the peripheral parenchyma 

 in groups corresponding to those formed within the longitudinal 

 muscles. It is evident that this grouping is gradually extending 

 toward the surface of the body, though it has not yet reached it. 



Fir,. 51. 



In other words, there are in this region of the neck localized re- 

 gions of growth, or regions in which the nuclei multiply more 

 rapidly than in the intervening, regions and now these areas of more 

 rapid growth are gradually extending toward the surface of the 

 body. All of the figures being drawn to the same scale, it is 

 evident that the growth in width of the body has begun. 



In Fig. 52 the proglottids are well defined and their boundaries 

 are indicated upon the surface by shallow furrows. The body is 



