88 



The Naturalist. 



if we remember that the functions of plants are remarkably uniform 

 even in the most widely separated forms, and that in consequence, blink 

 the fact as we may, here, as in the other moiety of the organic world, the 

 best classificatioas are essentially morphological. In speaking of fungi, 

 therefore, it will be understood that I do so in the sense and with the 

 limitations indicated. For use, the term is simply a physiological one, 

 and is not intended to connote either morphological or classificatory 

 distinctions. 



Another matter that perhaps needs a word of explanation is the 

 meaning to be attached to the phrase "sexual reproduction." In the 

 m )re highly organised plants, as among the higher animals, the sexual 

 organs are so different, at least in external form, and the act of fertiliza- 

 tion is attended with so many subordinate but co-operating processes, 

 that its essential character is more or less obscured. By the study of 

 lower forms, however, it becomes obvious that all that is required to 

 constitute a true case of sexual reproduction is the fusion of two indi- 

 vidualised fragments of protoplasm, derived either from distinct plants 

 or from different parts of the same plant, whose coalescence is the 

 starting point of a longer or shorter series of changes in the fused mass, 

 that ultimately issue in the production of one or more individuals 

 specifically identical with the parent. 



The fact that a process of this nature obtains to any extent among 

 fungi has only been demonstrated within very recent years, through the 

 investigations of Tulasne, De Bary, Pringsheim, Van Tieghem, and 

 others, and, strange though it may seem, has hardly received from 

 English botanists the attention its importance deserves. I have thought, 

 therefore, that a brief account of the principal results that have already 

 been obtained would be interesting to the members of our Society, and 

 might stimulate the working botanist to attempt the verification, and if 

 possible the extension of the observations that have been recorded. 



In the most recent classifications of the vegetable kingdom, the fungi 

 are distributed, as already indicated, among the four classes of thallo- 

 phytes, termed respectively ProtopJiyta^ Zijgospore(B, Oosporea^ and Car- 

 posporece, and I shall best attain the object I have in view by considering 

 the fungoid forms of each of these in order. 



Protopliyta. In the class of protophytes we have a number of fungi 

 arranged under the heads of ScJiizomycetes and Saccharomyces. The 

 former includes the somewhat numerous forms of Bacteria, and the latter 

 the so-called Torula, or yeast fungus. In the ScJiizomycetes multiplication 

 always takes place by transverse division. In Saccharomyces it is brought 

 about by gemmation, or budding, and by the endogenous formation of 



