60 DIVISION I.—GENERAL MORPHOLOGY. 
It is a universal histological law that every spore is the daughter of one or some- 
times more than one mother-cell, which is consequently called the spore-mother-cell. 
There are many and great differences between spores and their mother-cells in 
respect of their special qualities, structure, and mode of formation, and in respect of 
their position in the life-history of the species and the homologies which result from it, 
and several different kinds of spores may be formed in the course of development of a 
single species. Hence there are several categories, kinds, or forms of spores and 
spore-mother cells, that may be distinguished according to these different points of 
view. In their terminology these distinctions are expressed sometimes by adjectives, 
sometimes by compounds of the word spore, as swarm-spores, ascospores, &c., some- 
times also by special words, gonrdium, ascus, basidium, and others. Each of these 
terms signifies a spore or its mother-cell in the general meaning of the word above 
indicated, with a definite specific reference. A fuller explanation of the terms and 
an account of the reasons for their adoption are reserved for Chapter IV. 
The distinction between spores and their mother-cells on the one hand and 
vegetative cells on the other is naturally drawn first of all from cases in which the 
differences are most distinctly marked, and these constitute the large majority. It is 
to be expected that in a large and much graduated series of forms some would occur 
in which those differences would be less marked, sometimes indeed be almost 
obliterated. As examples of this may be mentioned the vegetative form described on 
page 4 as Sprouting Fungus, in which each sprout may be quite rightly termed a spore 
in the above acceptation of the word, and in the gemmae formed by the abjunction of 
cells with the power of germination from the vegetative hyphae in the Mucorini, 
Tremellineae, and Ascomycetes, which will be subsequently described. No confusion 
would be caused by a consistent use of the word spore in these cases. Whether it 
would be convenient that other terms should be introduced in its place is a matter to 
be determined by judicious agreement in each case. 
Many of the peculiar characters of spores and many of the phenomena attending 
their formation and ripening recur in the most different groups of the Fungi, and 
would necessarily be included in a general survey. Others again are confined to 
individual groups and can only be fully discussed with them. At the same time we 
shall, I believe, get a clearer view of the whole subject ifthe second series of characters 
is considered along with the first, and those points only are reserved for special 
description in Division II which are quite irreconcilable with such general treatment ; 
among these are especially questions concerning homologies and sexual relations 
which are still in many respects obscure and debatable and must be considered in 
each individual case. 
a 
1. DEVELOPMENT AND SCATTERING OF SPORES. 
Section XV. According to our present views on the origin of cells, every cell is 
the daughter of a mother-cell, and except in the cases of conjugation and rejuvenescence 
is formed by a process of division which takes place in the mother-cell?. Either all 

" I pass over for the present the conjugation and coalescence of cells for reasons of convenience 
which have been partly intimated above; this subject will be considered in Division II. Reju- 
venescence I exclude because it is not the formation of a new cell, but only the transformation of a 
previously existing cell. 
