INTEODUCTION TO CRYPTOGAMIC BOTANY. 243 



its mycelium than the bud of a Rafflesia to its tLallus, if such 

 it may be called. The two cases, in fact, are strictly analo- 

 gous. Allowing, then, to every Fungus a vegetative system 

 and a fructifying system, we shall first have cases in which 

 the two are confluent; and when once the fructifying system 

 gains a marked ascendancy, we shall have every conceivable 

 variety which can arise from the composition of the fractifying 

 threads, consistent with their main end of producing fruit, 

 and not merely of exposing the largest surface possible to the 

 influence of the surrounding elements, though that end may 

 sometimes be secured concurrently with the other. Though 

 nutriment is undoubtedly derived from the matrix on which 

 the mycelium grows, it is not to be denied that much may be 

 imbibed by the surface of the fructifying mass, which comes 

 in aid of the small portion which could be carried up by the 

 comparatively diminutive myceUum. The mycelium, however, 

 will stUl convey the elements which are necessary for the 

 peculiar species, the matter derived from the air being the 

 same in all cases aHke, whether fluid or gaseous. According 

 to the degree, therefore, in which the cells belonging to the 

 fruit are compacted, we shall have the free or fasciculate 

 cottony threads of moulds, the large and complicated spores of 

 rusts resting at once on the myceUum ; the waxy hymenium 

 of Pezizce and Corticia, the highly developed pilei of mush- 

 rooms, the homy perithecia of Sphcerice, and many other 

 forms, increased moreover by differences in the shape of the 

 component threads or vesicles, and the textmre of their cell- 

 waUs, and consequent powers of endurance. 



234. But there are differences too which depend upon the 

 nature of the fruit. The true fruit of Fungi is formed on two 

 separate plans ; in the first the tips or branchlets of certain 

 privileged threads or cells of the fructificative mass swell into 

 bodies, surmounted by little spicules which gradually give rise 

 each to a single cell, whose endochrome is either condensed into 

 a single mass, or becomes compoxmd by the formation of mem- 

 branous partitions. This mode of fructification is called 

 acrosporous, and obtains amongst the most highly developed 

 Fungi. In such cases the spore ultimately falls off ; and in the 

 16 * 



