CELLULAR DIFFERENTIATION 



6i 



Fig. 30, 



FiGt 30. Diagram of nervous and cross-striate muscular tissue, showing the mode of connec- 

 tion between nerve fibres and muscle fibres. A, nerve cell (g) connected with muscle fibre (m,f.) 

 by nerve fibre («./-). The muscle fibre (m./.) is composed of numerous fibrils (/) which are made up 

 lengthwise of alternating discs of lighter and darker substance. These fibrils are shown more 

 highly magnified in B and C. In B the fibril is uncontracted; in C it is contracted. D, nerve fibre 

 more highly magnified showing a, axis; m, medullary sheath; and 5. Schwann's sheath; ax., axon; 

 d, dendron; n, node; n.m., nerve-muscle plate. 



