62 



DIVISION I -GENERAL MORPHOLOGl'. 



sense of the word and the cell from which they spring is the basidium. In species of 

 more simple character both expressions are used according to convenience. Among 

 the manifold variations in individual cases which must be left for special description 

 there are at the same time a number of generally recurring phenomena according to 

 the mode of abjunction, the numerical relations, and the ultimate shedding of the 

 abjointed portions. 



As regards \h& form which may be exhibited by the phenomenon, the cross 

 septum may appear beneath the apex of the sporiferous cell, the apex itself being 

 usually expanded : the portion thus delimited is the spore ; the breadth of its base is 

 about equal to that of the sporiferous cell. The simplest examples are most uredospores 

 (Fig. 26) and the teleutospores of Uromyces. A second case is that in which branches 

 grow at certain points from the sporiferous cell and these are either abjointed at the 

 point of insertion, which usually becomes much constricted after the manner of the 

 t 



FIG. 26. Pticcinia graminis. 

 Small piece of a hymenium; 

 uresdospores with four germ-pores 

 in their equator, t a pair of teleu- 

 tospores, the upper with a germ- 

 pore in its apex. Magn. 390 times. 



FIG. 27. a~ d Aitricularia Auricula Jiidae. Development of basidia and spores ; 

 successive stages of the development according to the letters, a cylindrical terminal cell 

 of a hypha from which several basidia are formed by transverse division b ; each of the 

 basidia puts out a long narrowly conical sterigma (f, d) from its upper extremity, and the 

 swollen apex of the sterigma is abjointed as a spore s; xa sterigma from which the spore 

 has fallen, f the development of the basidia of Exidia sficitiosa, Sommerf; four basidia are 

 formed from the cell / by divisions crossing one another in the cell ; the other parts of the 

 figure show younger and later states ; s a spore. The dotted lines indicate the surface of the 

 hymenium. ./after Tulasne highly magnified, a d magn. 390 times. 



sprouts in the species of Sprouting Fungi (p. 4), or they elongate into slender stalks, 

 sterigmata in the narrower sense mentioned above, and their swollen extremity forms 

 by abjunction a spore. Examples, to be again noticed, are to be found in the 

 Basidiomycetes, in Eurotium, Penicillium, Haplotrichum, Peziza Fuckeliana, &c. 

 Intermediate cases occur, as might be expected, between the extremes and 

 require no further description. 



A sporiferous cell or basidium may produce only one reproductive cell by acro- 

 genous abjunction, or several, even many, may be formed. The first is the case in 

 most species of the former cf the two categories just mentioned, for instance in the 

 uredospores of Puccinia, Uromyces, and others. The basidia of Entomophthora are 

 examples of the second case, and those of most species of Tremella, Exidia, and 

 Auricularia Auricula Judae with long sterigma-shoois, the swollen apex of which 

 becomes a spore by abjunction (Fig. 27). 



