24 H, MARSHALL WARD. 



than below what was expected — is attended with unlooked for diffi- 

 culties. Not 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 multiplied, 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 conditions of various kinds affect their develop- 

 ment, and that the complete life-cycle of any one fungus — and evi- 

 dence based on a thorough knowledge of this is alone admissible for 

 the purposes of science — may present various forms of complexity. 



Even to-day, notwithstanding the considerable additions to our 

 knowledge derived from the study of development, and notwith- 

 standing that we possess several comprehensive generalisations as to 

 the curious changes undergone by typical forms in their development, 

 we are far from possessing sufficient 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 addi- 

 tion 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 development ; 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 statement succeeds, it may be that we have 

 helped to advance matters after all. 



If, however, further criticism results in the overthrow of the hypo- 

 thesis brought forward at the conclusion, we may nevertheless hope 

 that some service is rendered in arranging the facts, and drawing- 

 attention to the necessity of employing physiological as well as mor- 

 phological considerations in the attempt to construct a phylogenetic 



