251 



On Nucleated Sporidia.. 

 By M. C. Cooke, M.A. 



{Read August 2bt7i, 1871.) 



The section of British Fungi to which I desire to' draw more 

 particular attention is that group of Helvellacei, which are asso- 

 ciated together under the generic name of Peziza. This genus is 

 represented in our islands by between 150 and 200 species, all of 

 which are characterised by their cup-like form, and more or less 

 fleshy substance. They range in size from a point just, distinguish- 

 able by the naked eye, to at least four or five inches in diameter. 

 In colour there is a great variety, — some having bright carmine, 

 vermilion, or ccerulean tints, and others of more modest browns, 

 greys, or snowy-white. In many instances the outside of the cup 

 is granular, hairy or woolly ; whilst in others it is perfectly smooth. 

 All these features are taken into account in the determination of 

 species. The structure of these fungi are the points of greatest 

 interest to the microscopist, and can best be studied in some such 

 large species as Peziza aurantia, or Peziza vesiculosa, neither of 

 which are uncommon. If we take one of these cup-shaped fungi 

 when mature, in its fresh state, and cut it down through the centre, 

 we shall observe first that the outside and inside of the cup varies 

 somewhat in texture, as well as in colour. That the inside has 

 usually a smooth, delicate, waxy appearance, and, if exjDOsed to the 

 light for a few minutes, little smokey puffs of the minute spores will 

 from time to time be ejected from the surface, as of miniature dis- 

 charges of fairy artillery. By cutting a thin slice from the cut 

 surface of the section and placing it under the microscope, a good 

 notion of its general structure will be obtained. The slice should be 

 as thin as a sharp knife and a steady hand can accomplish. If this 

 slice be placed in a drop of water, or pure glycerine, on a slide, 

 and covered with thin glass, then submitted to a slight pressure, it 

 may be examined freely with a quarter inch objective. Towards the 



