182 



BOTANY 



Most of the Agaricaceae are saprophytes, growing most commonly 

 upon soil rich in humus or decaying vegetable matter, but many of 

 them grow also upon animal excrement, like the common genus 

 Coprinus (Fig. 147), several species of which usually appear spon- 

 taneously upon horse-manure which is kept for a week or two under 

 a bell-jar. The common field Mushroom (Fig. 148), also, grows 

 especially well in pastures which have been enriched by the drop- 

 pings of animals. 



B 



sp 



FIG. 147. Coprinus. A-H, development of the fruit-body in Coprinus sp. A-C, 

 slightly enlarged, the others more highly magnified. D, section of young lamella. 

 E, hymenium with mature basidia and cystidium, x. F, young basidium, with 

 developing spores. G, H, young fruit-bodies. /, conidia of C. lagopus. (I, after 

 BREFELD.) 



The mycelium in these forms spreads extensively through the 

 substratum, and in the Mushroom must have a long period of growth 

 before the fruits begin to form. Occasionally, as in Coprinus lago- 

 pus, branching filaments may arise from the mycelium, upon which 

 conidia are borne ; but usually the only type of spore developed is 

 the basidiospore. 



The formation of the fruiting-body begins in a small, compact mass 

 of hyphse (Fig. 147, G-), which are at first entirely similar. In most 



