158 ANATOMY OF THE YEAST CELL. 



fuchsine, decolorised, and finally stained by immersion in a 30 

 per cent, aqueous solution of picric acid. This colours the integu- 

 ment red and causes the granules to stand out clearly fi'om the 

 surrounding plasma, which is stained yellow. Even during the 

 life of the cell, the granules will absorb certain dyestuffs, for 

 instance when, as recommended by Eisenschitz, cells of yeast 

 are cultivated in beer wort containing an addition of a i per 

 cent, solution of Benzopurpurin. Some of the granules will 

 stain red by this method in one to two days. 



In addition to these granules, which can be detected at once 

 in the unchanged living cell, there are, according to Hieronymus, 

 other similar inclusions, which only become visible after the 

 cells have been fixed with, say, chromic acid or hydrochloric 

 acid. When this treatment has been followed by staining, the 

 " central filament" is found to be surrounded by an abundantly 

 looped chain of granules embedded in the portions of the plasma 

 adjoining the wall. 



Nearly every one of the workers hitherto named has re- 

 corded a certain power of locomotion on the part of the struc- 

 tui'es in question, though the reports on the extent of this 

 power differ. It was remarked by Raum and then confirmed 

 by Hieronymus, that in many instances (though not invariably) 

 a gradual migration of granviles from the parent-cell into the 

 young bud goes on during the formation of a daughter-cell. 

 This is represented in Fig. 155. The movement of the granules, 

 however, proceeds very slowly, and bears no comparison with 

 the brisk saltatory motion (Brownian movement?) noticeable in 

 the bodies often observed in the vacuoles of many yeasts, and 

 which are indeed so plentiful in the cells of Mycoderma as to 

 constitute a characteristic of this mould fundus. Divergent 

 opinions prevail on the nature of these vacuolous inclusions (so- 

 called saltatory bodies), some regarding them as being invading 

 bacteria, others as endogenous cells, or as dead plasmal excre- 

 tions. J. Raum was the first to observe the entry of these 

 bodies from the plasma into the vacuole; and it was then shown 

 by E. KuESTER (I.) that this migration could be induced by 

 allowing the yeast cells to dry on some substratum. According 

 to the reports of Eisenschitz, a reversal of this migi-ation — 

 namely, from the vacuole back to the suiTOunding cell plasma, 

 may occasionally take place. The chemical construction of these 

 saltatory bodies can no longer be regarded as identical with that 

 of the plasma granules, since E. Kuester has shown that the 

 two differ in certain I'espects as regards their behaviovir towards 

 dyestuffs. This notwithstanding, neither he nor Symmers (IL) 

 later on, succeeded in arriving at a definite solution of the 

 problem. 



In many instances it is observed that the granules offer a 

 greater resistance to decomposition than any other constituents 



I 



