REPRODUCTION OF MYCODERMA. 413 



mountain peak with a number of dichotomous branches running 

 down into the plain ; or again, a miniature volcano, whose 

 uniform slopes, covered with powdery white dust, exhibit a 

 number of supplementary craters in the form of small, warty 

 excrescences. Other colonies are broad and round, like cakes, 

 with superficial fissures through which the pasty mass is exuding 

 in the form of a round protuberance"; or again, like a cake the 

 substance of which has subsided along radial lines." These 

 descriptions of Lindner's, however, are only applicable to a few 

 typical Mycoderma species. MEISSNER (XI.) classes the giant 

 colonies of the Mycoderma races examined by him into four 

 different types, according to their habit of growth. Type No. i 



FIG. 194. Giant colony of Myco- FIG. 195. Giant colony of Myco- 



derma from Geisenheiin currant- derma from Gau-AIgesheim grape- 



juice. Nat. size. juice. Nat. size. 



comprises smooth colonies, the members of which differ in their 

 lustre, the fluting at the edges, the extent to which they grow 

 into and liquefy the gelatin medium, and in a smaller degree by 

 their size and colour. Type No. 2 includes the circular, compact 

 colonies, which differ in size and superficial markings. In type 

 No. 3 the colonies are also compact, but exhibit more extensive 

 markings on the surface (Fig. 194). In type No. 4 the colony is 

 raised in the centre, sinking thence, with a concave slope, to a 

 ring concentric with the original cell. Radial lines extend from 

 this ring or wall to the edge of the colony ; and between these 

 lines, irregular depressions and excrescences (Fig. 195) can be 

 observed. As regards the microscopical examination of the 

 cells, it will be noticed as shown by WILL (XIII.) and 

 MEISSNER (XL) that the cells around the edge of the colonies 

 are larger than those nearer the centre. 



In the case of stab cultures, WILL (XIII.) showed that the 

 species examined by him which grew to a depth of 60 mm. into 

 the gelatin was able to bear a certain degree of deprivation of 

 air. The streak cultures of Will's species failed to exhibit any 

 characteristic features at the end of 1 5 days. 



