MITOCHONDRIA IN TISSUE CULTURES 391 



In the cells of tissue cultures neutral red stains only a few gran- 

 ules unless used in such strong solutions as to stain the entire 

 cytoplasm. In such cases a few clear unstained spaces were seen, 

 but a study of the living cell and of the same cell fixed after 

 the neutral red stain by means of osmic vapor and stained with 

 Bensley's anilin fuchsin, methylen green stain demonstrated that 

 the clear space seen in the cells stained with strong neutral red 

 solution are only the unstained mitochondria. 



The description of the Binnennetz given by Perroncito ('11) 

 certainly resembles in many ways the behavior of the mito- 

 chondria in the tissue culture cells. He finds a network which 

 is like that sometimes seen in these cells, and the 'corona' of 

 granules shown in some of his figures appears very much like 

 the mitochondria granules radiating out around the central body. 

 In some of our permanent preparations where vacuoles are 

 present these spaces have all the appearance of the canalicular 

 system. 



Prolonged fixation in osmic acid did not reveal the canalicular 

 system, although the mitochondria became slightly blackened 

 by the action of the osmic acid. However, none of the special 

 stains for the canalicular system were used, as we desire to deal 

 only with the structures seen in the living cell. 



Amitosis and giant cells 



Many cells of these growths contain two or more nuclei and 

 the membrane within the nucleus, which Childs ('07) described 

 as connected with amitosis, is occasionally seen in such cells, 

 but no definite relation between such cells and the mitochondria 

 has been observed. Certainly in some giant cells containing 

 many nuclei, the number of mitochondria present is far greater 

 than that present in a normal cell of the same growth, in fact, 

 it is so much greater that it seems to be definitely related to the 

 amount of nuclear material and to the extent of the cytoplasm. 

 These cells show clearly that there is some other method of 

 increase in the number of mitochondria than that of division 

 at the time of mitosis, for these giant cells appear to be formed 



