TOWLE. 



[VOL. II. 



clumps of disintegrating muscle tissue. The outlines of the 

 inner fibers are somewhat less distinct than in the preceding 

 stage, and some of the bundles seem to be splitting up. This 

 condition is represented in Fig. 2. Most significant is the fact 

 that at no stage is any karyokinesis found among the muscle 

 fibers, although the increase in the number of nuclei is enormous. 

 Passing through Region II of this stage, the number of old 

 fibers decreases and the scattered nuclei increase, until at the 



FIG. 2. 



plane where the cut was made all old fibers disappear and we 

 reach Region III, which is made up entirely of closely crowded 

 nuclei, each surrounded by a small amount of protoplasm. 

 Karyokinesis is first seen in II, a short distance above the cut, 

 among the outer cells, never in t/ie muscle fibers, and the num- 

 ber of dividing cells increases toward the growing tip until it 

 becomes quite large. 



In the fifth stage a further difference is to be noted. We 

 find in Region I, in the inner part of the limb, the old muscle 



