Figure 10. Developing striated muscle (nn lo-hyoid) from a frog-embr\-o ot the 

 23rd day. The fibrillation is taking place in a continuous syncytium, in which 

 the developing fibrils can be traced for considerable distances. Observe that 

 each fibril is composed of a longitudinal row of dots arranged very definitely in 

 pairs. . Each pair constitutes the rudiment of Bowman's element. In some 

 places it will be observed that some of these pairs of dots are becoming trans- 

 formed into dumbell shaped structures. X 1000. 



