CHAPTER IV.—INTRODUCTION, 131 
accordingly be termed a sporocarp of a very simple kind; here we have the more 
comprehensive name implying a more comprehensive relation. If we succeed in 
getting a clear general idea of these modes of expression, which necessarily vary 
in all cases according to the various points of view, we shall have no difficulty in 
finding the term that is suitable to each particular case. It will be well to do this before 
proceeding to the consideration of the Fungi which often have so great a variety 
of spores. 
Historical and critical remarks on the terminology. The word sdore, together 
with the related term sporangium and others, is found first in Hedwig (Descriptio 
musc. frondos. Lips. 1787), who uses it in the same sense as ‘semen’ and promis- 
cuously with it. It was next employed by L. C. Richard (Démonstr. bot. ou Analyse 
du fruit, 1808) under the form of sforu/a, and distinctly defined as the small body, 
functionally corresponding to the seed, in agamous plants, i.e. plants which have no 
embryo. Link (Elem. Phil. Bot. 1829) again introduced the words spore and sporangium, 
and adds the word sdorzdium for objects as to which it was not clear whether they 
were spores or sporangia; in the Fungi for instance he calls (1. c. p. 359) the acrogenously 
formed spores of Penicillium and Aspergillus sporidia. The construction of the true 
cell-theory necessarily resulted in the recognition of the fact that spores are repro- 
ductive cells. Fries (Syst. Mycol.) generally uses the word sporidium for the spores 
of Fungi. Berkeley (Introd. to Crypt. Bot. p. 269) terms endogenously formed spores 
sporidia, using the word spores for those that are acrogenously formed. These attempts 
to confine the term to special formations have been repeatedly made, but none of them 
could meet with decided success for the reason already given in the text. The mode 
of expression adopted in section XXXI, which limits the use of the word sporidium 
to spores abjointed from promycelia, was introduced by Tulasne in his work on the 
Uredineae and Ustilagineae. In species in which different kinds of spores had been 
observed, the difference in their position in the course of development, the difference 
in their homology as we should now say, has long been clearly recognised and fully 
appreciated. The expression spore or sporidium was then limited to those bodies 
which could be regarded as homologous with the spores of Mosses, having or appear- 
ing, though without sufficient reason, to have an equal ‘dignity’ with them. This 
idea was nowhere distinctly expressed, but was nevertheless everywhere implied. 
The other spores therefore which made their appearance in the course of develop- 
ment ending in the formation of these ‘spores’ required another name. Wallroth 
(Naturgesch. d. Flechten, 1825) called them goridia, on the ground, it is true, of some 
misinterpreted observations (see Division III), and this term, though occasionally 
discarded, has maintained itself or been resumed, as has been partly noticed above. 
Kiitzing in the Phycologia generalis (1843), where the account of the matter has some 
of the old obscurity, A. Braun (Verjiingung, p. 143) and other writers may be 
consulted. In the Fungi Fries (Syst. Mycol. especially Band III, pp. 234 and 263) 
substituted the older word conidium for gonidium, clearly implying that the conidia 
answer to the gonidia of plants which are not Fungi. 
Fries found his especial and most distinct examples of conidia in the Erysipheae 
(1. c. 234). Since the conidia are formed by acrogenous abjunction in these Fungi 
Fries seems to consider this as their only mode of origin, and to have chosen the 
name he gave them from their forming a powder or dust (xovia) on their conidiophores. 
He did not mean that all acrogenously abjointed spores were conidia, but all conidia 
are acrogenously abjointed. As this view is often in accordance with the facts, 
and men are strongly influenced by the word which they have been taught, the 
expression used by Fries has unintentionally given occasion to confusion, because 
while conidia were said to be of acrogenous origin, spores acrogenously formed were 
opposed as conidia to other spores which were formed endogenously, in spite of 
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