VARIOUS OBSERVATIONS 



61 



submerged gill ridges overgrown and covered by a superficial 

 development of the hyphae of the parasite. There is therefore a 

 pyrenomycetous perithecia-containing stroma covering the aborted 

 gills of the agaric and thus adding to the thickness of the flesh. 



The parasitised fungus, when full-grown, instead of emitting 

 a cloud of basidiospores, emits a cloud of ascospores (Fig. 19, A). 

 I gathered some fruit-bodies, took them to the laboratory, and 



FIG. 18. Vertical sections through two fruit-bodies of Lactarius piperatus attacked 

 by Hypomyc.es lactifluorum. The gills are undeveloped. The under side of 

 the*pileus is thickly dotted with perithecia. Found in woods at Winnipeg. 

 Natural size. 



placed them in their natural upright positions in a large glass 

 damp-chamber. On the next day, I removed one of them and so 

 placed it in still air that a beam of sunlight passed underneath 

 its pileus. Immediately I perceived that the Hypomyces was 

 discharging its spores. A steady thin cloud of spores, every spore 

 glistening in the sunlight, was maintained for some time. While 

 some of the spores were being borne away by slight air currents, 

 others newly ejected took their place beneath the pileus, so that 

 the cloud was constantly rejuvenated. The distribution of the 

 perithecia was about nine to each square millimetre of pileus 

 surface (Fig. 19, B) ; and, since the area beneath the pileus covered 



