REPRODUCTION OF MYCODERMA. 411 



acid stained the cell wall dark brown, a result that MEISSNER (XI.) 

 did not succeed in obtaining in the case of wine Mycoderma. 

 This behaviour on the part of the membrane led Will to conclude 

 that substances behaving like fats or oils were stored up in or 

 upon the membrane. The same worker (XI.) has also pointed 

 out that the microscopical examination of Mycoderma cells has 

 revealed the presence of individuals characterised by a certain 

 lustre, accompanied by a bluish sheen. This peculiarity he 

 ascribes chiefly to an enveloping stratum of air ; and this conclu- 

 sion was confirmed by MEISSNER (XI.). The higher lustre of 

 the cells may also be the result of their content of glycogen, 

 which varies considerably in the individual cells of one and the 

 same culture. As is the case with the cells of Torulacece, the 

 contents of young Mycoderma cells have a low refractive power 

 (see p. 391, vol. ii.), and consist, according to WILL (XIII.) of a 

 somewhat fluid substance that is stained by iodine. They must, 

 therefore, contain a large proportion of water. The vacuoles, of 

 which at first there are three, four or more in each cell, after- 

 wards coalesce to form one or two. No highly refractive bodies (oil 

 particles) can be observed in the very young cells ; but when these 

 cells are treated with iodine, deeply stained, dense granules become 

 visible in the places where the refractive bodies are found in 

 more mature cells. At the end of forty-eight hours these granules 

 can be perceived without the aid of the reagent. By the third day 

 they number from one to three, and are situated either at the 

 ends of the cells, or one of them is in that position, whilst the 

 other lies between two vacuoles at one side or in the middle. At 

 the same time the vacuoles are more clearly visible, and exhibit 

 a denser plasinal integument. At the end of forty-eight hours 

 the cells will give a faint glycogen reaction with iodine. In 

 aged cells crystalloids are gradually developed in the vacuoles, 

 the oil particles come into being and attain considerable dimen- 

 sions (2 JJ, in diameter). These latter are stained a blackish brown 

 by osmic acid. According to Will the oil particles differ from 

 those in old yeast cells by remaining unstained when treated 

 with concentrated sulphuric acid, though, as with yeast cells, the 

 oil is expelled from the cells on the addition of the acid. Further 

 particulars on this point, and on the position, structure and sub- 

 division of the cell nucleus, will be found in chapter xlvii. 



304. Reproduction of Mycoderma in and upon 

 Various Nutrient Media. 



As already stated on p. 408, vol. ii., all the Mycoderma species 

 reproduce by budding, which process has been described on p. 9, 

 vol. ii. At present we will merely deal briefly with the formation 

 of the bud aggregations, characteristic of the pastorianous 



