2o6 Sphacria Morbosa. 



proved that many fungi take on different growths under varying circum- 

 stances, it has become a matter of considerable question how far the 

 autonomy of these obscure vegetable growths can be established. 



The group to which this particular fungus belongs, is, however, tolerably 

 constant in character. The genus Sphaeria is well defined, if we include 

 the newer genera made out of the old genus by later writers, more for the 

 convenience of treating of so vast a number of species, it seems to us, than 

 on account of difference worthy of generic distinction. These carbonaceous 

 papillate fungi are so well defined in their peculiarities as to be readily 

 identified by those familiar with their forms. Yet even these vary ; and, 

 when closely proximate forms are found on different plants, a question 

 arises whether they are identical or not. The young growths of the wild- 

 cheriy {Cerasus serotmd) are often found covered with a fungus very similar 

 to the Sphaeria jnorbosa. Indeed, almost any woodland border will furnish 

 plenty of specimens. The perithecia are smaller, and are sometimes pro- 

 longed into a short beak. The cherry belongs to the same order as the 

 plum ; and it may be that the parasitic fungus infests both, but is swayed 

 by influences in both plants so as to develop differently. We have seen 

 branches of the cultivated cherry similarly affected. The size of the spores 

 is considered a good specific character, and yet these vary. 



It has been thought by some that the peculiar growth of the bark which 

 bears this fungus is occasioned by the sting of a curculio ; but any one 

 familiar with the stroma of fungi will understand that this growth is char- 

 acteristic of a whole family, and arises, not from insect poisoning, but from 

 fungus influence. The insects, seduced by its soft, pulpy character in its 

 early stages, may deposit there their eggs, as it is not unlike the flesh of 

 unripe fruit in texture, at one period. Various methods have been devised 

 to stay the ravages of this fungus. Sulphur placed in holes made in the 

 trunk of the tree has been resorted to ; but we imagine that there are no 

 sure preventives. When we remember the excessively minute size of the 

 spores, we can understand that they may be absorbed with the nutriment 

 of the tree, or taken into the stomata of the leaves, and carried into its 

 tissues. Fungi infest wild plants as commonly as cultivated ones ; a proof 

 that their occurrence is not necessarily due to an unnatural or deteriorated 

 state of the plant they attack. Charles % Sprague. 



Boston, February, 1867. 



