I 12 



CHILD. 



at various stages of its history. Fig. 63 shows one half of the 

 proglottid. The longitudinal muscles and the nephridial canals 

 are indicated. Examination of this series will show clearly that 



FIG. 62. 



almost the whole increase in the width of the proglottid is due to 

 the growth of the central parenchyma, the peripheral parenchyma 

 forming little more than the posterior extensions at the margins. 



FIG. 63. 



In the growth in thickness of the body, /. e., in the dorso-ven- 

 tral direction, the central parenchyma is not so markedly pre- 

 dominant. The three regions seen in a sagittal section preserve 



f 



FIG. 64. FIG. 65. FIG. 66. FIG. 67. 



much the same proportions during the growth of the proglottids 

 (Figs. 64-70). In this series Figs. 66 and 67 show respectively 

 the contracted and extended conditions in proglottids of the same 

 age. Figs. 68 and 69 show similar conditions in a later stage. 

 Fig. 70 is from a nearly "ripe" proglottid. In this series it is 

 seen that the peripheral parenchyma has undergone about the 



