334 
Journal of Agricultural Research 
Vol. I, No. 4 
its connection with a previously described Coniothyrium occurring upon 
some widely differing host. An ^numeration of the characters thus far 
observed is given below. 
It should be stated that the pycnidia have been observed mostly in 
culture, their formation on the host having been confined to the extracted 
kernels in a damp chamber. In the latter case their development has 
has taken place at or near the surface of the kernel and often accompanied 
by a thin subicle of brown to whitish hyphae. 
Coniothyrium caryogenum, n. sp. 
Upon pecan kernels Coniothyrium caryogenum causes dark-brown, irregularly round¬ 
ish surface spots with a hemisphere of pithy tissue beneath, which is surrounded by 
a brownish layer of host cells. 
Mycelium brown, sometimes almost hyaline where not submerged, septate, slightly 
branched, straight or within the host cells often separating into the constituent hyphal 
cells which are then more or less swollen and thick walled. 
Pycnidia roundish, osteolate, thin walled, dark brown, about 200 to 2 50 g. in diameter. 
Sporophores short and indistinct. Spores pale brownish, elliptical, i-celled, 2.5 to 
3.6 by 1.8 to 2 fi. 
Habitat.—Kernels of Carya illinoensis (Wang.) K. Koch. Typ e specimens from 
large seedling tree belonging to Mr. James R. Vann, Thomasville, Ga. Specimens also 
received from Raleigh, N. C.; Baconton, Ga.; Monticello, Fla.; Minden, La., and 
other points in the pecan belt, including Texas. 
CROWN-GALL 
[Caused by Bacterium tumefaciens Sm. and Town.] 
So far as known, the crown-gall has not hitherto been published as 
occurring on the pecan from natural infection. However, in the fall 
of 1909 specimens of young trees affected with both the hard and soft 
types of galls (PI. XXXVI) were received from a nursery in Mississippi 
with the statement that about 0.1 per cent of the stock in the nursery 
was infected. The disease has also been observed by the writer at one 
point in northern Florida. But, since these two localities have fur¬ 
nished the only cases reported, it may be considered as of very rare occur¬ 
rence upon this host. 1 
On the pecan the tumors occur not only at the collar of the tree but 
several inches higher up on the stem and also on the roots. The greater 
prevalence of the disease near the surface of the ground is explained by 
the fact that the parasite first enters the host tissues through wounds. 
Thus, the process of grafting and the subsequent treatment of the stock 
readily furnish conditions requisite for infection and further develop¬ 
ment. The typical appearance of the disease may be inferred from the 
name; the galls at first consist of a succulent growth of the young host 
cells thrust out from the cambium layer in the form of a tumor which 
may attain a considerable size. With age the surface becomes much 
1 The only practical method of control hitherto employed consists in rigid nursery inspection. Obviously, 
no trees showing the disease should be planted, even though the pecan does not appear to be as seriously 
affected as many other plants. 
