250 



RESEARCHES ON FUNGI 



stipe has its axis vertical and the pileus with its 

 gills is symmetrically situated upon it. The two 

 deepest gills shown in Fig. 85 are gills which, when 

 seen in lateral view, stretch from the stipe to the 

 periphery of the pileus, while the three gills of lesser 

 depth are not attached to the stipe and therefore 

 have a shorter length (cf. Fig. 87). 



The outlines of forty-two successive gills which 

 were removed from about one-sixth of a small pileus 

 are shown in Fig 86. The gills naturally fall into 

 three classes : (1) long gills which extend from the 

 stipe to the periphery of the pileus, (2) gills of 

 medium length which extend only a part of this 

 distance, and (3) short gills which are present only 

 at the pileus margin. The two deepest gills and 

 the three gills of lesser depth in Fig. 85 evidently 

 correspond respectively to the long gills and gills 

 of medium length in Fig. 86. The total number of 

 gills in the small fruit-body from which the forty-two 

 gills were removed was about 240, and the hymenial 

 area supported by all the gills together was estimated 

 to be about 88 square centimetres. 



A fruit-body usually begins its development 

 toward the base of a dung-ball, to which it becomes 

 firmly attached by an extension of the base of the 

 stipe in the form of a gelatinous layer or mass 

 (Figs. 83 and 87). The stipe, on beginning to 

 elongate, is ageotropic but positively heliotropic : 

 it therefore grows towards the light. The pileus at 

 this stage is small, hard, and conical, so that it can 

 be pushed with relative ease by the heliotropic stipe 

 past obstacles into the open. After the pileus has 



, , , . ., ., ., .. - 



been brought into the open, the apical portion of 

 ^ 8 ^P G becomes strongly negatively geotropic and 

 ceases to respond to the stimulus of light. The 

 stipe, therefore, as it completes its elongation, grows vertically 

 upwards ; and, since the pileus is attached to the stipe-apex in 



FIG. 86. Panaeolus 



campanula*. The 



gills from about one- 



