184 STRICKLAND: NOTES ON FUNGI. 



And now a word as to the difficulties in the way of identifying 

 species. In the case of the Hymenomycetes these difficulties are 

 rapidly disappearing, thanks to the admirable series of plates in course 

 of publication by Dr. M. C. Cooke ; henceforth it will be an easy 

 matter to identify British species by comparing them with the plates, 

 although much, I imagine, has yet to be learnt as to the variability 

 of the different genera and species. Fungi, so wonderfully rich 

 in varieties of form, are more than any other large group of 

 plants parasitic and epiphytal ; whole genera of minute fungi are 

 specifically named from their hosts; consequently, the species would 

 seem to have been evolved posterior to the evolution of the genus, 

 and, in many cases, of the species, of the host. What are we to say, 

 for example; of Oidium chartarum which is specified as growing 

 upon paper, or Zasmidium with its predilection for dark cellars and 

 wine-bins ? We may, I think, infer that very many species of fungi, 

 unlike the patriarchal diatoms and foraminifera, are of comparatively 

 recent date, and from their great diversity of form and wide distri- 

 bution it may also be inferred that, like the higher Phanerogams, 

 they are liable to considerable variation in the present day. However, 

 I will return to this subject by-and-bye. It is in the case of the 

 minute fungi that the difficulties of identification are still rife, and a 

 feeling of dissatisfaction is apt to be left in the mind after the most 

 careful examination and comparison. Sometimes the specimen in 

 the herbarium is found to be destitute of the characteristic fruit, and 

 a complete comparison with the specimen for identification cannot 

 therefore be made. Sometimes the specimen for identification is 

 itself defective. Then again, mycology being a recent branch of 

 natural history, the series of specimens in the herbarium is by no 

 means complete, and the student is thrown back upon the technical 

 descriptions in the handbooks — descriptions which, unless the host 

 is very specific or the individuality of the species well marked, are 

 often liable to mislead, from the indefinite pictures which they produce 

 in the mind. Here it is that the worker may find a useful field for his 

 labours. What is wanted are good and abundant specimens, with the 

 date of finding recorded, together with the habitat and the nature of 

 the host. There should also be a careful sketch of the fructification 

 as well as a note of the colour of the spores or sporidia. This 

 sketch should be made of the apparent size of the object under the 

 object-glass, and the power of the object-glass should also be noted. 

 No species should be admitted unless the normal fructification is 

 present. Abnormal fructification should be specially noted, but the 

 species should be kept separately. Careful sketches of fructification 

 are particularly needed amongst Ascomycetous fungi ; most of all 



Naturalist. 



