ON THE SEXUALITY OF THE FUNGI. 263 



only is the isolation and cultivation of any given fungus an 

 extremely difficult matter, but the following it through all the 

 phases of its life-history brings the observer face to face with 

 problems of quite a special nature. 



As time progressed and observations raultipliedj it became 

 clear that the Fungi are by no means so simple as they perhaps 

 appeared. Apart from practical difficulties of manipulation, 

 consequent on their minuteness, number, and intermixture 

 with other forms, it soon became evident that special condi- 

 tions of various kinds affect their development, and that the 

 complete life-cycle of any one fungus — and evidence based on 

 a thorough knowledge of this is alone admissible for the pur- 

 poses of science — may present various forms of complexity. 



Even to-day, notwithstanding the considerable additions to 

 our knowledge derived from the study of developments, and 

 notwithstanding that we possess several comprehensive gene- 

 ralizations as to the curious changes undergone by typical 

 forms in their development, we are far from possessing suffi- 

 cient knowledge of these matters to enable us to group the 

 Fungi satisfactorily from a phylogenetic point of view. This, 

 however, is a distinct aim of biology, and every addition to 

 knowledge in this direction is to be welcomed. 



In the present essay it is proposed to describe some of the 

 more recent and most suggestive observations on Fungi; and 

 especially on their reproductive organs, since it is in these that 

 the most important phenomena (from the phylogenetic point 

 of view) are centred. We shall have occasion to refer to, and 

 in part to trace certain processes connected with their develop- 

 ment ; and finally to see how far it may be possible to generalise 

 from the facts now known. 



In so far as this paper simply recounts observations — for the 

 most part made by others — it cannot claim scientific merit ; 

 but if, after condensing and arranging the facts, and stating 

 the condition of our present knowledge of the subject, the 

 attempt to bring this knowledge under a more general state- 

 ment succeeds, it may be that we have helped to advance 

 matters after all. 



