CHAPTER IV. INTRODUCTION. 13 f 



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 spore, together 

 with the related term sporangium and others, is found first in Hedwig (Descriptio 

 muse, 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 (Ddmonstr. hot. ou Analyse 

 du fruit, 1808) under the form of sporula, 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 sporiditirn 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 gonidia, 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 ((covt'a) 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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