4 DIVISION I. GENERAL MORPHOLOGY. 



hard as horn or wood, in the dark rind of the dry Pyrenomycetes, of the Tuberaceae, of 

 many sclerotia, &c., leave scarcely any intercellular spaces. Every intermediate stage is 

 to be found between the loose accidental intertwining of the socially growing Hyphomy- 

 cetes and the firm structure of the Fungi which have a definite form, and states 

 the farthest apart from one another sometimes occur in the same species. 



When the hyphae run parallel to one another, as in the stipe of Agaricus Mycena, 

 Coprinus and other species, their connection may be brought about by cementation 

 (Verklebung) or concrescence (Verwachsung) of the membranes, and in the same way 

 they often gain much firmness where they are interwoven with one another. In hard 

 tissues, as the rind of .many non-fleshy Fungi, and in the masses of gelatinous tissue 

 described on page 9, the outer surfaces of the hyphae are often inseparably grown 

 together, or are cemented together by a narrow slip of a firm homogeneous substance ' 

 in fleshy Fungi the hyphae are often united by an intervening substance which softens 

 in water and allows them to be artificially separated. This cementing substance 

 may be called intercellular substance. Whether it is to be regarded as a part of the 

 cell-membranes themselves or as an entirely distinct body from them, is a question 

 which in the case of the Fungi has not yet been specially examined ; there is therefore 

 the less ground for assuming other laws than those which prevail in the histology of 

 other plants. Lastly, the coalescence above mentioned of branches originally distinct 

 also adds to the firmness and solidity of the compound Fungus-body ; its occurrence 

 is shown in fleshy and gelatinous species by the frequency of H-shaped connections, 

 though no special researches have been made into their mode of formation. 



Of the exceptional cases referred to above in which the Fungus-thallus is not 



formed of hyphae, the first to be noticed 



M is that of the forms recently termed by 



Nageli Sprouting Fungi (Sprosspilze). This 

 name, like that of Filamentous Fungi, indi- 

 cates a growth-form; and this is the only 

 form in some Fungi, as in the species of 

 the genus Saccharomyces known as Yeast- 

 fungi, or it is peculiar to particular states of 



^^Cl^ jSfflP* other species which otherwise appear as fila- 



$ $ & mentous or compound forms. In the latter 



FIG. 3- SMHaronyc,: <****; a ceUs befor* CaS6S Jt ma y bfi * mattCr f d Ubt > for H^SOnS 

 sprouting, b-4 cells sprouting in a fermenting saccharine j u p hereafter disCUSSed whether the SnrOllt 

 solution; stages of development in the order of the letters. l Ue "CredUer UlbLUbSjCU, WUCUWT U1C S>prOUl 



Magn. 390 times. j s ^ Q ^ re g ar( j ec j as a vegetative or as a 



reproductive organ. 



The characteristic features of the Sprouting Fungi are as follows (Fig. 3). A 

 cell grows to a certain size and shape, the latter being usually spherical or somewhat 

 ovoid, and puts out an excrescence or sprout which remains connected with it by a 

 narrow base ; this new formation is of the same nature as .the parent-cell and is 

 separated from it by a transverse wall either before or after it has reached its proper 

 size. The process of sprouting may be repeated in the daughter-cell and in every 

 succeeding generation, the number of which is unlimited in presence of sufficient 

 nutriment. The number of sprouts that can be produced by each active cell and the 

 spots at which they appear are not certainly determined, though with regard to the 



