The Ohio Naturalist. 
[Yol. XIII, No. 8, 
158 
tinder the most favorable growing conditions, with the virus 
from tobacco plants. The inoculations had no effect. The virus 
from the tomato had just as little effect upon the tobacco plant. 
The tomato plants withstood the injections very nicely and did 
not show the least signs of distortion.” Clinton (1908) on the 
other hand states that he succeeded in producing mosaic disease 
on the tomato by inoculation with juice from a diseased tobacco 
plant, and from this tomato plant he transferred the disease back 
again to tobacco. 
Ts Mosaic Disease Inheritable ?—Investigators are almost unani¬ 
mous in the opinion that “calico” of tobacco is not inheritable. 
Woods (1902, p. 7 ) says, “There is no conclusive evidence that 
the plants from seed of diseased plants arc more subject to the 
disease than are those from the seed of healthy plants.” Iwan- 
owski (1903) conducted inoculation experiments with crushed 
diseased seed. He produced the disease in this manner just as 
readily as where he used diseased leaves. He states (p. Id), 
“From such facts one would conclude that the disease must be 
inheritable, but experiments do not show this to be so. ” In regard 
to this characteristic of mosaic disease Sturgis (1899, pp. 247-8), 
says that seed from diseased plants do not give rise to “ealicoed” 
plants. “It would seem apparent, therefore, that “calico” 
is not communicable through the seed. I secured from the 
seed bed—twenty seedlings showing “calico” and from the same 
bed, twenty apparently healthy seedlings. These were—set in 
two parallel rows in the garden—with one exception, all of these 
forty plants were badly ealicoed within six weeks. The exception 
was one of the originally healthy plants—most of the plants 
flowered and ripened an abundance of seed. This seed was sown 
in flats in the greenhouse. Of the hundreds of seedlings—thus 
raised not a single one showed a sign of “calico” in the flats. 
Thirty seedlings were transplanted and set in a row in the Station 
garden—. All of the plants—showed great vigor and remained 
perfectly healthy. Meantime, from the same lot of seedlings, 
a dozen were sent to Mr. Ackley, who set them in a warm comer 
near the barn—. These also failed to show any signs of “calico.’ ’ 
“ Tomato mosaic is an inheritable disease in contrast with tobacco 
mosaic.” these are the conclusions of Westerdijk (1910, p. 20). 
She kept the seed from apparently healthy looking fmit on a 
diseased plant, separate from that of mottled fruits. She sprouted 
the seed and the seedlings were transferred to the greenhouse, 
test plot and garden. Proper checks were used in all cases. 
All plants grew equally well at first, but in two or three months 
a noticeable difference was seen. In the field she raised 50 plants, 
grown from diseased seed; the parent plants having been arti¬ 
ficially inoculated. Also 46 were grown from diseased seed from 
greenhouse plants. Of the latter, 20 originated from mottled 
