448 BULLETIN OF THE BUSSEY INSTITUTION. 
the genus Gibbera near G. Vaccinit, Fr. It seems to us, on the whole, 
premature, so long as the complete history of so many of the different 
Spheriacee remains unknown, to place much confidence in generic char- 
acters of that order as at present defined. In estimating the system- 
atic position of any fungus, we must consider all its different states, 
and any classification based solely on one form of fruit, to the exclusion 
of others, must be unsatisfactory. The species of Gibbera have not 
yet been sufficiently studied to enable us to define the genus accurately ; 
and we should think it more correct to place the Spheria morbosa of 
Schweinitz in the genus Cucurbitaria, some of the species of which —as 
CO. Laburni, De Not., —it resembles in the stylospores and pycnidia, 
although the ascospores are different. The ascospores of the different 
species of Cucurbitaria, however, vary very much in appearance. We 
prefer to retain the generic name Spheria for the present, and wait 
until the genera of Spheriacee assume a more definite character, be- 
fore changing it. 
Turning, now, from the botanical side of the case, to the knot as a 
destroyer of fruit-trees, there is no end to the articles which have 
appeared in the journals, speculating on its cause or suggesting a 
remedy. We occasionally hear that the knot is a recent disease; but 
Mr. J. Buell states * that, in 1811, the plum-trees in Kingston, Mass., 
were almost all destroyed by the knot. Schweinitz,f speaking of its 
effects in 1822, says: “ Morbum lethalem Cerasorum et omnium 
Prunorum effecit.” In 1831,f he again refers to the Spheria morbosa 
as being much more common in Pennsylvania than in Carolina, and as 
being particularly injurious to cherries, which he calls in Latin 
“ Amarelle,” probably Morellos, and to the Hungarian and Reine 
Claude plums. From the sentence, “ Nuperrime autem et in his omni- 
bus Cynips fungusque incepiunt sevire et quidem magnitudine semper 
maxime aucta, sistentes tumores ad sesquipedalem longitudinem exten- 
sos,” it appears that he regarded the black knots as caused by the 
combined action of insects and Spheria morbosa. In 1819, Prof. W. 
D. Peck, of Cambridge, published an account of the insects found in 
the knots of cherry-trees, which he regarded as the cause of the knot 
itself. Dr. Joel Burnett, of Southboro’, Mass.,$ was one of the first to 
* “New England Farmer,” Jan. 20, 1826. 
t “Syn. Fung. Car.,” p. 40, No. 134. 
t “Syn. Fung. Am. Bor.,’”’p. 204, No. 1416, 269. 
§ “New England Farmer,” Aug. 16, 1843. 
