144 RESEARCHES ON FUNGI 



spores had been shot off the sterigmata just as in the Coprini. A 

 species of Psilocybe yielded a similar result. 



Method IV. — A piece of a gill of a Mushroom was i)laccd flat 

 in a closed compressor cell and observed from above Avith an 

 ordinary vertical microscope. An endeavour was made to see the 

 spores leave the sterigmata of individual basidia. It was argued 

 that, if the spores merely fall passively from the sterigmata, after 

 liberation they ought to lie below their respective sterigmata, 

 whereas, if they are discharged violently, they should often take 

 up other positions. 



Apparently ripe basidia were focussed and watched. After some 



X A B ^2 C ^2 D ^2 



3 4 5 4 .-^ ^^ ^^ ™ 



Fig. 52.— The successive and violent discharge of the four spores from the 

 basidiura of Psalliota campestris. Part of a gill was laid flat in a compressor 

 cell. The basidium looked upwards and was observed from above. X the 

 basidium, with its four rii^e spores. The appearance of the basidium imme- 

 diately after the discharge of spores I, 2, 3, and 4 is shown at A, B, C. and 

 D respectively. 



hours had been spent at this task, a basidium was seen to discharge 

 all its spores. Sketches were made after the discharge of each 

 spore and are reproduced in Fig. 52. When one watches the dis- 

 charge of a spore, all that one can see is that the spore suddenly 

 disappears from its sterigma and immediately appears again in a 

 new position on the hynienium. In Fig. 52, X shows the ap})ear- 

 ance of the four spores on the basidium before discharge, and 

 A, B, C, and D illustrate what was seen immediately after the 

 discharge of spores Nos. 1, 2, [3, and 4 respectively. It is clear 

 that the spore No. 2 (B) must have jumped over No. 4 to get 

 into the position it came to occupy after discharge. Similarly, 

 No. 4 (D) must have jumped over No. 3. A study of this case 



