THE JOINT-WORM. 
555 
straw produced by this wo mi, led me to suspect that the 
disease was identical with that which had been observed in 
barley-straw, and that it originated from the same cause. 
In the article above named, Dr. Fitch appears to have come 
to the conclusion that the disease was produced by some 
species of Cecidomyia. He found the disease of the wheat- 
straw to be situated immediately above the lower joint, in 
the sheathing base of the leaf, the substance of which, for 
a distance exceeding half an inch, was much swollen, and 
was changed to a more solid and wood-like texture, while 
the surface exhibited several long pale spots, slightly elevated 
like a blister. The hollow of the stem was entirely oblit- 
erated, at some parts, by the pressure of the enlarged por- 
tion of the sheath, and was hardly visible at others. Each 
of the blistered spots covered an elongated cavity, containing 
a footless worm or maggot, about ten hundredths of an inch 
long, of an oval form rather more tapering posteriorly than 
towards the head, and divided by slight constrictions into 
thirteen segments. The worm was soft, shining, of a uni- 
form milk-white color, with a small Y-shaped brown line 
marking the situation of the mouth. “ So exactly,” remarks 
Dr. Fitch, “ does this worm in its form and appearance 
resemble the larvae of the Hessian fly and other species of 
Cecidomyia which have fallen under my examination, that I 
entertain no doubt it pertains to the same genus of insects.” 
On the 10th of March, 1852, F. G. Iluffin, Esq., of 
Shad well, Virginia, the editor of “ The Southern Planter,” 
sent to me that paper for July, 1851, containing some 
account of the joint-worm, and with it a few samples of 
diseased wheat-straw. A much larger quantity of the 
straw, soon afterwards received from him, was divided 
into two unequal portions, the larger of which was sent 
to Dr. Fitch, in the hope that between us something defi- 
nite concerning the origin of the disease might be obtained. 
Upon examining my samples, I found that the disease 
was not invariably confined to the sheathing base of the 
