SUPERFICIAL MYCODERMA VEGETATIONS. 415 



and WILL (XIII.), is that the films produced by these fungi are 

 often perforated in the earlier stages, these open spaces closing 

 in, however, during the subsequent growth of the cells. This 

 phenomenon still lacks explanation. 



In consequence of the progressive growth of the cells, the 

 smooth, colourless film, as in the case of many film-forming 

 Torulaceoe,, becomes veined, folded and wrinkled, this taking place 

 sooner with some races than others. The initial folding differs 

 with the various races. According to the researches of Meissner, 

 the following four groups are well defined : the first group 

 exhibits broad veins, protruding upward like bubbles (Fig. 196). 

 In the second and third groups the width of the veins decreases 



FIG. 196. Mycoderma 

 from Eltvillered wine. 

 First stage of film for- 

 mation. Slightly re- 

 duced. 



FIG. 197. Mycodernia from 



Guben cider. First stage of film 



formation. Slightly reduced. 



FIG. 198. Mycoderma 

 from Berlin white beer. 

 First stage of film for- 

 mation. Slightly re- 

 duced. 



(Figs. 197 and 198). The fourth group exhibits similar veins, 

 but finer and of a decorative character. Under certain conditions, 

 more especially when isolated portions of the liquid are left un- 

 covered either in the mass of the film or against the edge of the 

 culture vessel, the veining of the film may be preceded by the 

 formation of parallel folds. As the film continues to grow, the 

 veining passes over into the mesenteric form or becomes linear. 

 In the former case the mass assumes the appearance of a loosely 

 woven fabric, the threads of which are all entangled. These 

 threads may be either coarse or fine. In the linear form the 

 lines proceed either from an eccentric point in the film, or from a 

 point on the glass wall (up which, in all cases of Mycoderma, the 

 cells climb a short distance), or again from several central points 

 on the film or from one of the open spaces thereon. The lines 

 running in one direction may also be uniformly distributed on 

 the film. During the further progress of growth, alterations 

 take place in the folding, cultures which were mesenteric at first 

 exhibiting wrinkles of various depths. According to MEISS- 

 NER (XL), there are five different types of corrugation: No. i, 

 resembling cauliflower ; No. 2 having shallower corrugations ; 

 No. 3 more uniform and finer ; No. 4 still finer ; No. 5 showing 

 very fine wrinkles. 



VOL. ii : PT. 2 2 D 



