52 RESEARCHES ON FUNGI 



some of the gills crowd one another unduly, and only a few of the 

 highest have room to turn so as to give themselves the chance 

 of successfully liberating spores. Some Mushrooms which had 

 undergone symmetrical development on an artificial bed were 

 picked and fixed so that the planes of their pilei were set in a 

 vertical direction. Previous to the experiment the gills looked 

 downwards in the most perfect manner, and the undersides of the 

 pilei presented the appearance shown in Plate IV., Fig. 25. After 

 being placed in their new positions the gills soon reacted to the 

 stimulus of gravity and attempted to make the usual adjustment. 

 However, owing to the fruit-bodies having been tilted through an 

 angle of 90°, this could not be successfully accomplished. A photo- 

 graph of the pilei, as they appeared at the end of the experiment, 

 is reproduced in Fig. 18. It will be seen therefrom that only a 

 very few gills at the top of each pileus remained separated from one 

 another. These liberated a few spores, which settled on the upper 

 sides of the extreme tops of the stipes. The rest of the gills had 

 become so crowded that they covered one another up. It is not 

 surprising, therefore, that practically no spore-deposit accumulated 

 on paper placed immediately below the pilei. 



It seemed of interest to find out to what extent the stipe of a 

 Mushroom is capable of undergoing curvature when the pileus 

 has been placed by artificial means in a very unfavourable position. 

 Accordingly, some Mushroom spawn was planted in large pots 

 containing horse manure covered with soil. After a few weeks 

 fruit-bodies duly made their appearance, but before they had 

 attained the size of peas their position was altered. Some of 

 the pots were suspended upside down and others fixed horizontally 

 on their sides. The soil was kept in place by the careful use of sticks 

 and wire netting. Under these conditions the fruit-bodies continued 

 to grow, and the stipe of each made an attempt to place the pileus 

 in the usual position. Where the pots had been inverted the 

 attempt proved to be almost a complete failure (Fig. 17, A), but 

 where the fruit-bodies grew out from the soil laterally it was 

 attended with a large measure of success (Fig. 17, B). Had the 

 fruit-bodies in the latter instance been larger and of more vigorous 

 growth, probably the success would have been somewhat greater. 



