SACCHAROMYCES 



127 



in close connexion. But, inasmuch as the budding is irregular, new 

 individuals sprouting out from any part of the surface of the cell, the 

 colonies or growth forms that arise are also irregular, branching out not 

 only in one plane, but in all directions, without any definite sequence of 

 growth (Fig. 25). The cells are often elongated, sausage-shaped, and the 

 tangled colonies or ' growth forms ' have then almost the appearance of 



FlG. 25. Saccharomyces. a, Saccharomyces cerevisiae, No. i. b, Sacch. Pasteurianus, No. 3. c, Sacch. ellips- 

 oideus (wine-yeast), No. i. d, Sacch. ellipsoideus, No. 2. e and f, pellicle growth (pseudomycelium) of Sacch. 

 ellips., No. i ; e, at ^o-2o or 6-7 ; f, at if-yoP. g-k^ spore-bearing cells ; g, Sacch. cerevtsiae, i ; A, Sacch. 

 Pasteur., i ; 2' and k, Sacch. ellips. , i and 2. /, germination of two free spores ofSaccA. LudwigiiaH i8"'-2o , from 

 left to right, after 18, 20, 26, 28, 29, 30$, and 33 hours respectively. All cultures in beer-wort, magn. 1000 (from E. 

 Chr. Hansen). 



mycelia (Fig. 25, e and g). Such pseudo-mycelial masses arise both 

 immersed in liquids and on the surface. In the latter position they often 

 unite to form membranes or pellicles (' veils '), as we saw was the case with 

 some bacteria. Their mode of origin shows them to be, however, not true 

 mycelia, but only ' growth-forms.' 



The yeast cells, like those of other plants, consist of a membrane 



