484 ASCOMYCETES. 



mere saprophytes and thus escape popular notice. The fruiting bodies 

 vary in size from those which are scarcely visible to the unaided eye to 

 more than a foot in diameter. 



The group is characterized by having their spores borne in closed 

 receptacles which are known as spore-sacs or asci, the number of spores in 

 each being very constant and vaiying in the following ratios : two, four, eight, 

 sixteen, thirty-two, etc. In many cases the spores at maturity are forcibly 

 extruded from the ascus like shot from a gun, and in such numbers as to 

 appear to the unaided eye like a cloud of smoke. They are then caught 

 up by the wind and widely disseminated so that the atmosphere is never 

 free from some of these minute bodies. 



One of the groups of Ascomycetes which is usually well represented 

 in tropical and subtropical regions is that commonly known as the 

 sooty moulds. These plants receive their name from the sooty appear- 

 ance of the superficial mycelium which overspreads the substratum often 

 for several inches. The plants of this group are for the most part epi- 

 phytic, that is they grow on living plants ^\ithout actually drawing their 

 nourishment from them. They usually feed upon the remains or excre- 

 tions of minute insects such as plant-lice, which in turn suck their nourish- 

 ment from the tissues of the plants on which they live. The fruiting 

 bodies consist of minute subglobose perithecia scarcely visible to the un- 

 aided eye which in turn contain the asci and spores. Many of the speci- 

 mens collected in Beraiuda did not show mature perithecia and for this 

 reason their identity is uncertain. Several mature specimens belonging 

 to the genera Meliola, Dimerospormm and Asterina were collected in 

 Bermuda. 



The Pyrenomycetes constitute a very large group of Ascomycetes 

 which also have their asci borne in closed or nearly closed perithecia, the 

 sooty moulds being often included with this group. The fruiting bodies 

 of the Pyrenomycetes are usually black, which has suggested the name. 

 In a few of them, however, the fruiting bodies are bright-colored. One of 

 the latter is Cordyceps, a fungus which grows on dead insects or their 

 pupae and of which one species has been collected in Bermuda. Whether 

 these fungi attack the insect while living there is some difference of 

 opinion, but it is not unlikely that they do. About thirty species belong- 

 ing to the Pyrenomycetes have been collected in Bermuda. Most of the 

 species collected are saprophytes and of no especial interest from an eco- 

 nomic point of view. 



Still another group of Ascomycetes of considerable size is known as 

 the Discomycetes or cup-fungi. As implied by the name, a large number 

 of the plants of this group are cup-shaped and vary in size from that of a 

 pin-head to the size of a tea cup, or in rare cases even a foot in diameter. 



While most of the Discomycetes are cup-shaped, some are club-shaped 

 or spathulate. To the latter belong the smooth and hmvy earth-tongues, 

 several species of which have been collected and, in fact, found to be quite 

 common in Bermuda. The plants grow on damp soil or among mosses, 

 are black in color, and reach a height of several inches. It is because of 

 their flattened form that they have come to be popularly known as '^ earth- 

 tongues." 



Of the true cup-fungi the species Lamprospora Planchoms, a small 

 purple cup-fung-us sometimes reaching a size of nearly an inch m diameter 



