"In answer to a communication of mine, Professor C. H. Peck, botanist, of Albany new York, informs me that he has found sacks filled with spores with in the perithecia of black-knot, and has furnished me with a sketch of the sack as seen by him, (see U, Fig. 17.) I represents a highly magnified view of the true spore of this for of Shaeria." -Watts, 1874

Black knot of the plum

"In answer to a communication of mine, Professor C. H. Peck, botanist, of Albany new York, informs me…