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TOWLE. 



[VOL. II 



and great excess of nuclei, there being often two or three to 

 one fiber and many outside the fibers. 



The later stages need not be described in detail. As the 

 limb grows longer the formation of new muscle tissue pro- 

 gresses farther down toward the tip, the new fibers being 

 always small and containing several nuclei. The number of 

 nuclei outside the fibers decreases, until in stage 1 1 the 

 muscles look quite normal, and the number of nuclei is exces- 

 sive only in the region of the foot, which is at this time 



FIG. 4. 



clearly differentiated. Karyokinesis is found, I believe, without 

 exception, near the growing end, never in the upper regions. 



The first appearance of any definite grouping of cells appears 

 in stage 5, where the arrangement into bundles is foreshadowed. 

 As the fibers form, the division into bundles becomes more 

 distinct, until in stage 1 1 they are all differentiated as far 

 down as the foot, and here we can see by the arrangement of 

 nuclei where the bundles are to be. 



In the process of regeneration described above there are 

 certain things to which I wish to direct especial attention. In 



