MITOCHONDRIA IN TISSUE CULTURES 383 



Brilliant cresyl blue 2 b, which is much less toxic than nile 

 blue B extra, shows a most interesting behavior on the part of 

 these vacuoles and granules. A vacuole may appear in the cyto- 

 plasm as a clear unstained space which at first contains no 

 granules, but within five to ten minutes the granules appear as 

 dancing bodies as though they were the result of some conden- 

 sation and precipitation within the vacuole. This process con- 

 tinues and the vacuole takes on first a pale violet color, but later 

 a bright pink, and the granules condense into one or two purple 

 granules. Then the vacuole exhibits various movements such as 

 sending out long pink streamers or threads or becoming U-shaped. 

 Such a vacuole may decrease in size until only the purple gran- 

 ule can be seen. When a cell which contains many vacuoles 

 is stained, all gradations between the pale non-granular vacuole 

 to the single purple granule can be seen. 



One of the many observations made upon healthy cells in 

 which vacuoles appear is given in full below (fig. 23) . 



10.45 A.M. 1 gtt. (1-100,000) brilliant cresyl blue 2b in Locke's 

 solution + 0.25 per cent dextrose was placed on the preparation. 



10.50 A.M. The cytoplasm remains clear, several purple granules 

 appear. The mitochondria are unstained, slightly refractive bodies, 

 the fat globules are unstained and highly refractive, the nucleus is 

 unstained, but the nucleolus is a pale blue (fig. 23 a). There is present 

 one vacuole in the cell, which is stained a brilliant pink and contains 

 a large purple granule. The vacuole sends off a long pink streamer 

 quite as long as the thread-like mitochondria but not so thick (fig. 

 23, vac. a.). The vacuole manifests great activity. The streamer at 

 times becomes detached from the vacuole and fades out. Again it 

 appears to be drawn into the vacuole or sent out from the vacuole. 

 Fig. 23 b. 



11.00 A.M. The streamer no longer appears, and the vacuole itself 

 begins to change shape (fig. 23 b) and continued until 11.30 when the 

 vacuole began to grow smaller and a deeper pink. It then remained 

 more or less quiet but grew much smaller in size. 



1.05 P.M. The vacuole again sent off a pink streamer which lasted 

 only two or three minutes, after which the small vacuole with one 

 large granule remained quiet. 



11.00 A.M. A small granule (x) at the other side of the nucleus moves 

 rapidly to and fro between the nucleus and the periphery several times 

 (fig. 23 c, d, e, f). A streamer of pink follows the purple granule until 

 at 12 noon while the granule moved rapidly towards the nucleus the 

 streamer broke off two pink granules which instantly faded out. 



