334 MICROSCOPIC STRUCTURE OF HIGHER CRYPTOGAMIA. 



reproduction seems to be effected. In addition to the " fructifi- 

 cation" which is commonly recognized by its projection from 

 the surface of the thallus, the researches of M. Tulasne have de- 

 tected a set of peculiar organs of much smaller size, not unlike 

 the male receptacles of Fuci (§ 205), to which he has given the 

 appellation of spermogonia. From the exterior of the cellular 

 filaments which line these cavities, a vast number of minute 

 oval bodies termed spermatia are budded off, which, when mature, 

 escape in great numbers from the orifices of the spermogonia. 

 They differ from ordinary antherozoids in being destitute of any 

 power of spontaneous movement ; but in this respect they are 

 paralleled by the spermatoid bodies of the Floridece (§ 206). As 

 their participation in the production of fertile spores has not yet 

 been demonstrated, we cannot yet indubitably assign to them 

 the character of " sperm-cells ;" although various considerations 

 concur to render their possession of this attribute highly probable. 

 The female portion of the generative apparatus, though some- 

 times dispersed through the thallus, is usually collected into 

 special aggregations, which form projections of various shapes; 

 these, although they have received a variety of designations ac- 

 cording to their particular conformation, may all be included 

 under the general term apothecia. When divided by a vertical 

 section, these bodies at their maturity are found to contain a 

 number of asci or spore-cases, arranged vertically in the midst of 

 straight elongated cells or filaments, which are termed paraphyses. 

 Each of the asci contains a definite number of spores (usually 

 eight, but always a multiple of two), which are projected fi-om 

 the apothecia with some force, the emission being kept up con- 

 tinuously for some time ; this discharge seems to be due to the 

 difterent effect of moisture upon the different layers of the 

 apothecium. When and how the act of fecundation is accom- 

 plished, is a matter still hidden in obscurity ; and the problem 

 is one which, owing to the difiiculties arising out of the dense 

 structure of the organs, will only be resolved by a combination 

 of sagacity, manipulative skill, and perseverance, on the part of 

 Microscopic observers who may devote themselves to the study. 

 208. In the simplest forms of Fungi, we again return to the 

 lowest type of Vegetable existence, namely, the single cell ; and 

 such, if perfect plants, would properly take rank among the low- 

 est Protophytes. But there is good reason for regarding many 

 — perhaps all — of those which seem most simple, as the imper- 

 fectly developed states of other Plants, which, if they attained 

 their full evolution, would present a much more complex struc- 

 ture. This is the case, for example, with the Torula cerevisice or 

 Teastplant, which so abounds in Yeast, that this substance may 

 be said to be almost entirely made up of it. When a small 

 quantity of yeast is placed under the Microscope, and is magni- 

 fied 800 or 400 diameters, it is found to be full of globules, which 

 are clearly cells ; and these cells vegetate, when placed in a fer- 



