MITOCHONDRIA IN TISSUE CULTURES 



343 



Fig. 1 Photograph of part of a 2-day culture of intestine from an 8-day chick. 

 The black mass is the explanted piece, which is surrounded by the new growth 

 of connective tissue and smooth muscle; there are 13 mitotic figures in this part 

 of the culture ; osmic vapor and iron hematoxylin. 



Although several different kinds of cells have been identified 

 in the living cultures (Lewis and Lewis) as, for instance, the 

 mesenchyme and connective tissue cells, the heart and smooth 

 muscle syncytium, the endodermal membrane, the yolk mem- 

 brane, the nerve cell, the kidney tubule cell, etc., nevertheless, 

 the general cytoplasmic structure of the living cell, regardless 

 of the kind of cell, is practically the same except in cases where 

 the cells contain secretory granules. The cytoplasm appears 

 as a homogenous substance within which are several types of 

 granules, i.e., refractive fat globules, various shaped mitochon- 



