130 DIVISION II.—COURSE OF DEVELOPMENT OF. FUNGI. 
In this system of nomenclature the gonidium (3) for example of Oedogonium 
and Vaucheria would be a swarm-spore (2); the oospore of these genera would be 
non-motile spores, like the zygospore of Spirogyra; but the zygospore of Aceta- 
bularia and Botrydium is a swarm-spore, and all oospores are at the same time 
carpospores, and so on. The terminology indicated under 3 apparently comes so 
near to that of Sachs, that the question may be asked why the latter should not be 
accepted as the foundation of the system ; it will be well therefore to point out once 
more the fundamental distinction between Sachs’ terminology and that now proposed. 
With Sachs spores and gonidia stand side by side as different things; in this work 
carpospores and gonidia are special phenomena subordinated to the general con- 
ception of the spore. On practical grounds, which have been to some extent 
already indicated and which will be further explained below, as under the Basidiomy- 
cetes, we cannot do without a word to express this general conception as defined above. 
The terminology here proposed is therefore by no means unnecessary, as it might 
appear to be if ‘we confine our attention to Ferns, Mosses, and some types of 
Algae. 
The terminological sketch which has now been given supplies a scheme which is 
drawn from actual phenomena forming the general rule, and is applicable to them. 
But the highly complex reality is not designed after a single scheme ; there are inter- 
mediate forms connecting phenomena which are separated in the scheme, exceptions 
to the rule, and no terminology can take all these exceptions equally into account. 
In such cases the systematic terminology must necessarily be modified to suit the 
particular occasion. This must not be forgotten either here or in connection with 
the objects which will be described in the succeeding chapter. 
A spore proceeds to a further development if the conditions are favourable. 
The commencement of this further development is termed germination. Germina- 
tion considered morphologically consists in a very large majority of cases in the 
construction of the vegetative body of a unit-bion, as for example when Fungus- 
spores put out germ-tubes, as described above in section XXXI. But there are 
other cases also. Not only are there those in which the plantlet growing from a 
spore remains a rudiment morphologically and in this condition is devoted to 
special functions, as in the germinating androspores of heterosporous Pteridophytes 
or the pollen-spores of flowering plants, but there are others in which the germinating 
spore produces other spores directly as daughter-cells and is entirely expended in 
forming them, as was described above in section XXXI in the case of certain Fungi. 
In other words in such cases the germinating spore becomes the mother-cell or 
receptacle of spores of the next higher generation, a sporangium, as such receptacles 
are generally termed. The same object viewed in the different relations specified 
above may equally well be called a spore or a sporangium. The same thing may 
occur in spores of the most different morphological value, as in the oospores of 
Oedogonium and Sphaeroplea and in the gonidia of Cystopus. Spores which are 
strictly homologous and come from nearly allied species may develope, some as 
sporangia, others as a rudimentary thallus; for example, the gonidia of Peronospora 
(section XXXVII), the oospores of Oedogonium on the one hand and on the other 
those of Vaucheria. The homology between the spore-forming oospore of Oedogonium 
and the sporocarp of a Moss has been already pointed out, and the former may 
