M. C COOKE ON MICROSCOPIC MOULDS. 49 



again about nine hundred species of these, and scarcely one which 

 can be called microscopic. 



The next family is characterised by having the hymenium, and 

 consequently the spores, enclosed in an outer covering, or peridium. 

 Such for instance are the puff-balls. These are called Gasteromy- 

 cetes because of this character. Mixed with the spores threads are 

 sometimes developed, and in some cases the spores are formed upon 

 these threads. In the Myxogastres the relation which subsists 

 between the threads and the spores has not been satisfactorily 

 determined. Amongst the most interesting genera in this family 

 are Trichia and Arcyria. 



The remaining two families are truly microscopical. The 

 Coniomycetes, to which the greater part of my volume on u Micro- 

 scopic Fungi " is devoted, and the Hyphomycetes, to which our 

 attention is presently to be directed. The first of these has 

 the spores as the most prominent feature, and the latter the threads 

 upon which the spores are borne. The "smuts" and "brands" 

 may in some sense be taken as the type of one, and " blue mould " 

 of the other. It is only partly that the common objects I have 

 named can be regarded as types of the two families, because they 

 only represent in many of their features a section of the family. 

 The " smuts," for instance, cannot be accepted as a representative 

 of a Diplodia, in which the spores are enclosed in a distinct peri- 

 thecium, and is a sort of Sphooria without the asci ; nor of such 

 a genus as Excipula, which is pezizceform, but without the com- 

 pound fruit. 



Not to weary you with technicalities, or by indicating analogies 

 between forms which I may assume are unknown to the majority 

 of the members, I will proceed to describe the general structure 

 which prevails in the Hypthomycetes, or Moulds, hoping that those 

 who are familiar with the subject will, for the sake of those who 

 are not, censure me gently if my observations should seem to be 

 too elementary. There could be no stronger evidence of the small 

 interest which microscopists generally take in this subject than the 

 fact that in a club of five hundred members it was nearly two years 

 before a sufficient number could be induced to unite in the forma- 

 tion of a class for the study, or to obtain the preliminary infor- 

 mation necessary for the study, of these neglected organisms. 

 Perhaps in no country in Europe, with equal advantages, are 

 fungi so little known or studied as in Great Britain. There is 



