62 DIVISION I.—-GENERAL MORPHOLOGY. 
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 the 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 


FIG. 26. Puccinta graminis, FIG. 27. a—d Auricularia Auricula Fudae. Development of basidia and spores ; 
Small piece of a hy jum; 2 ive stages of the development according to the letters. @ cylindrical terminal cell 
uresdospores with four germ-pores of a hypha from which several basidia are formed by transverse division 5; each of the 
in their equator, 7 a pair of teleu- basidia puts out a long narrowly conical sterigma (c, @) from its upper extremity, and the 
tospores, the upper with a germ. swollen apex of the sterigma is abjointed as a spore s; x a sterigina from which the spore 
pore in its apex. Magn. 390 times, has fallen. /the development of the basidia of Extdia spiculosa, Sommerf.; four basidia are 
formed from the cell 5 by divisions crossing one another in the cell; the other parts of the 
figure show younger and later states; sa 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 of 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-shoots, the swollen apex of which 
becomes a spore by abjunction (Fig. 27). 
