4 i4 RESEARCHES ON FUNGI 



spores, after attaining full size, remained colourless for about two 

 hours. Then the process of pigmentation of the spore- walls set 

 in, and the walls continued to deepen in colour for about two 

 hours. After pigmentation of the spores had been completed, 

 the spores remained on the ends of their sterigmata for about 

 three hours and ten minutes. At the end of this time they were 

 shot away. The time taken by a spore to develop from a tiny 

 rudiment on the end of its sterigma up to maturity and ultimate 

 discharge was approximately eight hours. 1 



An Analysis of the Hymenium of the Cultivated Mushroom.- 

 The analysis of the hymenium about to be given is similar to that 

 for Panaeolus campanulatus. 



Any small portion of the hymenium, such as that which is 

 included within a dark or a light area of a gill and which has 

 begun to shed spores, is made up of the following elements : 



1. Past-generations Basidia, 



2. Present-generation Basidia, 



3. Coming-generation Basidia, 



4. Future-generations Basidia, and 



5. Paraphyses. 



On any small portion of the hymenium the basidia come to 

 maturity in a series of successive generations, and the para- 

 physes the permanently sterile elements undergo gradual enlarge- 

 ment during the progressive exhaustion of the basidia in exactly 

 the same manner as has been already described for Panaeolus 

 campanulatus. 



The arrangement of the various elements of the hymenium 

 in respect to one another iii surface view is shown semi- 

 diagrammatically in Fig. 146. On account of the small size of 

 the basidia and paraphyses and the consequent increase in the 

 optical difficulties of investigation, it was not found possible to 

 make camera-lucida drawings showing the positions of all the 

 elements in an actual surface view of the hymenium. Fig. 146, 

 however, gives a synthesis of a number of detailed observations 

 and is sufficiently correct. It will be found to agree in all 



1 Cf. Chap. II. 



