CHAPTER III. SPORES OF FUNGI. 6 1 



the constituents of the mother-cell enclosed within its cell-wall take part in this 

 process, and the whole of the mother-cell is parcelled out into daughter-cells, or one 

 portion of protoplasm only including the nucleus is separated from the other parts 

 and applied to the formation of daughter-cells, while the remainder is not used for 

 this purpose, but is subsequently turned to account in some other way. The former 

 process bears the traditional name of cell-division the latter, from an original 

 misapprehension, is termed free cell-formation. The expressions total and partial 

 division would better describe the phenomena as they are understood at the present 

 day. 



Both modes of cell-formation occur in the formation of the reproductive cells 

 which we are considering ; in the majority of cases the division is total. Asci afford 

 beautiful examples of the so-called free cell-formation. In some cases, as in the 

 formation of the spores of Mucor and the Saprolegnieae, it may be a question to 

 which of the two types they belong. Excepting such doubtful cases, all cases of total 

 division are cases of bipartition with formation of firm partition-walls. Of the details 

 of the process of division we know no more than we know in the case of the division 

 of vegetative hyphae ; we can only say that a partition-wall makes its appearance. 



The following are the chief modes of formation of spore-mother-cells and spores, 

 distinguished from one another partly by the differences which have just been 

 indicated and partly by peculiarities of form which present themselves in the process 

 of division. 



SECTION XVI. i. Intercalary formation (Intercalare Bildung). A delimitation 

 (Abgrenzung) takes place of portions in the growing hyphae, and the cells constituting 

 them become distinguished by their form and structure, acquire the characters of 

 spores or spore mother-cells, and at length become free by the gradual decomposition 

 or swelling of the parts that support or connect them. Their position is not uniform 

 in the cases that are known to us. 



Normal formations of this kind are the resting spores of Protomyces, 

 Cladochytrium, the spores of Entyloma, and the not infrequent cases of the formation 

 of gemmae already briefly mentioned *. 



2. Acrogenous abjunction 2 (Acrogene Abgliederung). Delimitation of the 

 extremities of hyphal branches with limited growth takes place by means of trans- 

 verse septa for the purpose of forming reproductive cells, which are therefore placed, 

 at least during their formation, at the apex of a stalk or sporiferous structure named 

 since Le'veille' basidium or sterigma (ascus suffultorius of Corda). In more highly differ- 

 entiated species the basidium is the peculiarly formed terminal cell of a hyphal branch, 

 and the spores are frequently the extremities of slender stalk-like ramifications of this 

 cell. In this case the actual stalks of the spores are termed sterigmata in a narrower 



1 [See the sections in which the Mucorineae and Tremellineae are described. 



2 The distinction between ' Abgliederung' and 'Abschniirung' (see section XVII) finds no ex- 

 pression Jin English botanical terminology, whilsfthe idea implied in both has been rendered by the 

 term ' abstriction.' If this term could be restricted to what is designated by ' Abschniirung,' it might 

 be retained as satisfactory ; but unfortunately it has come to be used so generally in the sense of 

 ' Abgliedemng,' that to avoid confusion it is altogether discarded in the text and the term ' abjunction ' 

 (with the verb to ' abjoint ') is introduced as rendering ' Abgliedemng,' and ' abscision ' (with the 

 verb to ' abscise !> l is used to express ' Abschniirung.'] 



