' 1876.] The Black Knot. 341 
median line,—that have given him the name of tesselated 
darter, said by the books to be “common.” But Boleosoma is a 
_ braver name, and we even prefer “ Boly,” for short. The head 
resembles that of Diplesium, but the habit of leaning forward over 
a stone, resting on the front fins, gives a physiognomy even more 
frog-like ; his actions however, are, rather bird-like, for he will 
strike attitudes like a tufted titmouse, and he flies rather than 
swims through the water. He will with much perseverance push 
his body between a plant and the side of the aquarium, and bal- 
ance himself on the slender stem. Crouching cat-like before a 
snail-shell, he will snap off the horns which the unlucky owner 
pushes timidly out. But he is often less dainty, and, seizing the 
animal by the head, dashes the shell against the glass or a stone 
until he pulls the body out or breaks the shell. “ Boly,” alas ! 
is the “ Quaker of our aquarium ” only in appearance. 
pai an eee 
THE BLACK KNOT. 
TEE following article is an abstract, by Mr. B. D. Halsted, 
of a paper by Prof. W. G. Farlow published in the Bulletin of 
the Bussey Institution of March, 1876. It will be the endeavor 
to give, with the aid of two of the three original plates,! a brief 
notice of the most important points concerning this destructive 
ungus, 
sightly, black, wart - like excrescences, with which every one is 
familiar, on plum-trees and different kinds of wild and cultivated 
“ierries. It is found in all parts of our country east of the 
Rocky Mountains, and is so common and destructive that in some 
ma be formed of the small crop of plums now raised in New 
i ae from the fact that two dollars and a half were given in 
oston last autumn for a peck of damsons for preserving. In 
k parts of New England, particularly in Maine and along 
° Sea-coast, the raising of cherries has also been almost aban- 
1 : 
The Sum of $500 was voted by the Trustees of the Massachusetts Society for 
ap seta Agriculture to aid Professor Farlow in his researches, and from this liberal 
p Priation the expense of the plates was defrayed. Professor Farlow is himself 
Sole for the Microscopic details of the plates, but whatever of beauty they may 
ZoBon ‘5 entirely due to the skill of Mr, J. H. Blake, of the Museum of Comparative 
ogy, Cambridge. 
