MOULDS, ETC. 



301 



germinal matter ; ultimately a mere trace of life remains, 

 which, taking the form of an impalpable powder, is free to 

 be driven hither and thither with every breath of air. 



From these facts we maj conclude that it matters little 

 whether we take yeast, achorion, or penicillium spores ; 

 the resultant is the same, and depends much more on the 

 food or nourishment supplied, whether the pabulum con- 

 tains more or less of a saccharine, albuminous, or nitro- 

 genous material, lactic acid, &c., together with light and 

 temperature ; whether we have a mould (green or blue), 

 an achorion, or yeast fungus produced. Diversity of form 

 in the cells, as well as quality and quantity of their 

 material contents, are certainly due to, and in a manner 

 regulated and controlled by that beautiful law of diffusion, 

 which admits, separates, sifts, and refines the coarser from 



Fig. 161. — Fungi. (Magnified 200 diameters.) 



1, Brachycladlum peniciUatum, growing on the stem of a plant. 2, Asperfjlllus 

 glauciLS, growing on cheese, &c. 3, Botrytis ; the common form of mould on 

 decaying vegetable substances. 4, Sphmria, fungi caught over a sewer (foul 

 air). 5, Fungi growing on a pumi^kin. 6, Fungi caught iu the air at the 

 time of the cholera visitation, 1854. 



the finer, the lighter from the denser particles, through 

 the porous structure of the cell-walL 



