PLUMS AND PLUM CULTURE IN MICHIGAN. 235 



FUNGOID THEORY. 



la the American Journal of Horticulture for April, 1867, may be found a 

 very scientific and carefully prepared article, contributed to that periodical by 

 Charles J. Sprague, a horticultural observer of considerable note, in which he 

 assumes, with a good degree of plausibility, that the excrescence in question is 

 a fungus, known to naturalists under the specific name of *' Sphaeria Moriosa." 

 We quote the article somewhat at length as follows : 



" The Sphaeria Morhosa is a fungus, belonging to a very extensive group, 

 which infests the bark of trees and shrubs. The different species are found in 

 myriads throughout the whole vegetable kingdom ; sometimes preying upon 

 living tissues, more frequently parasitic, upon decaying matter. They vary in 

 their mode of attack, or rather they occur in different parts of the plants which 

 support them. Some are superficial upon the bark ; some are immersed in the 

 subcuticular layer, bursting through the cuticle, erumpent as they are termed; 

 others take possession of the inner bark, and so affect it as to occasion an un- 

 natural and excessive development ; a corky, irregular, watery growth, which 

 finally bursts the outer cuticle, and covers the infested branches with unsightly 

 excrescences. To this latter group belongs the Sphaeria Morlosa. The fleshy 

 growth which it induces in the plum tree, or at least that portion which is 

 immediately occupied by it, is called its stroma. This is, at first, a homogene- 

 ous mass, presenting no definite character. By and by it takes on a reddish 

 coloration, which finally deepens into black ; the surface becomes carbonaceous 

 in texture, and is studded all over with minute papillae. A section of the stroma 

 will then exhibit a woody center with a carbonaceous rind. In this rind are 

 innumerable little rounded cavities, the upper walls of which constitute the 

 before mentioned papillae ; these are pierced by a minute hole, through which 

 the spores, or germinating processes, escape, the whole cavity and its walls being 

 CdMQ^ 2l perithecium. The spores are infinitesimally minute, oblong bodies, 

 contained, generally eight in number, in diaphanous sacs, or envelopes, called 

 asci, which develop from the ends of filaments, which line, in a dense mass, 

 the whole bottom and sides of the cavities. These are not carbonaceous like 

 the walls, but are of a gelatinous consistency. Imagine an egg-shell, from the 

 inner walls of which grow a dense mass of soft bristles half an inch long, on the 

 ends of which are little whitish, sausage-shaped sacs, containing oval bodies 

 lying diagonally in the sacs, one applied to the other, sidewise, the bodies being 

 variously lined, and you have a tolerable idea of the immensely magnified per- 

 ithecium, with its filaments, asci, and spores. 



•' That this structure we have just described should be a plant; that this 

 hard, black, charcoal-like substance should be vegetable, will seem strange to 

 those unfamiliar with the study of similar growths; but it is vegetable, and 

 has so permanent a character as to constitute a species. It must be allowed, 

 however, that it is a matter of doubt, in mycology, how far the same fungus 

 may be affected by the plants upon which it fastens, so as to change its habits 

 and appearance. The older mycologists named the host of parasitic fungi after 

 the plants upon which they were found; taking it for granted that they were 

 all distinct species, if they had a different look. Schweinitz, the great pioneer 

 of the study in this country, has enumerated a vast quantity of them in this 

 way; but, since later observations have proved that many fungi take on differ- 

 ent growths under varying circumstances, it has become a matter of consider- 

 able question how far the autonomy of these obscure vegetable growths can be 

 established. 



