THE MUSCULATUEE AND CONNECTIVE TISSUE. 



689 



rdle in the equipment of the eggs, and were, in other words, as v. 

 Siehold first precisely defined them, yolk-glands. 



Fig. 361. — TransTerse sections through the body of Bothriocephalus lotus. 

 A, At the level of the cirrhus-pouch ; B, In the posterior half, through the 

 female generative organs. The testes, uterine horns, yolk-sacs, and nerve 

 cords are also seen. ( x 10.) 



The Muscle Layers, like the reproductive organs, are disposed as in 

 the Tasnice. It is not of much importance that the longitudinal 

 fibres of the cortex are more thickly packed towards the yolk-glands, 

 and therefore towards the outside, than in the neighbourhood of the 

 central layer, which in the Tmnice, on the contrary, exhibits the 

 greater number of fibres. Nor is it very remarkable that the muscu- 

 lature of this Bothriocephalus is inferior in strength and degree of de- 

 velopment to that of the large-jointed tape-worms, and especially to 

 that of T. saginata. There is further a difference between the two 

 forms, in that the sagittal fibres of Bothriocephalus, instead of being 

 uniformly distributed, are in the middle layer for the most part 

 grouped in strands, forming a sort of framework in which the 

 testicular vesicles and the uterine coils are embedded. In the 

 younger joints this disposition is not yet perceptible ; it only arises in 

 consequence of the increase in the size of the generative organs, by 

 which the adjacent fibres are pressed to the side. 



The Connective Tiss^ie consists of cells of unusual size, and more 

 sharply defined than in the case of most Cestodes. This is in 

 part due to the nature of the protoplasm, which is marked off as an 

 almost gelatinous clear mass from the duller intermediate substance, 

 and in part also to the development of a fibrillar network, which 

 envelops the cells in its meshes. The vesicular tissue in the median 

 region is most distinct and beautiful, especially in the neighbour- 

 hood of the cirrhus-pouch, where the cells not unfrequently grow 

 to the size of 0026 mm. and more. The fibrous network is here most 

 strongly developed, and may be frequently observed to be of distinctly 

 muscular character, since the fibrils are seen to come into connection 



with the processes and. terminal branches^of the true muscle -fibres. 

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