9 6 



CHILD. 



camera, and thus correspond as nearly as possible in number and 

 position with those in the actual sections. The subcuticular 

 layer, however, is represented schematically by stippling. 



i. STRUCTURE OF THE NECK-REGION AND FORMATION 



OF PROGLOTTIDS. 



Behind the scolex there is a region some five to eight milli- 

 meters in length, commonly known as the neck, in which no 

 division into proglottids is visible externally. 



A few words regarding the structure of the body in this region 

 will render the following description somewhat clearer. 



FIG. 42. 



FIG. 43. 



Figs. 42 and 43 are transverse sections through the region 

 between the scolex and the point where distinct proglottids ap- 

 pear. Fig. 42 is taken from a section near the scolex, Fig. 43 

 from one further back. The lines 42 and 43 in Fig. 46 (p. 98) 

 indicate respectively the approximate levels of the two sections. 

 The proglottids are just becoming visible externally at the pos- 

 terior end of Fig. 46. 



The outer cuticular membrane is indicated by the line bound- 

 ing the figures. Beneath this is a cellular layer, the subcuticular 

 layer, with rather closely packed nuclei, indicated schematically 

 in the figures by the stippled region beneath the cuticle. At this 

 .stage of development the nuclei appear to lie in more than one 

 row. Beneath this cellular layer is found the parenchyma. The 

 portion of the parenchyma external to the longitudinal muscles I 

 have, for convenience, designated as the peripheral parenchyma 



