178 
4 
Scribner, F. L. Diseases of the Irish Potato. Bulletin of the Agricult¬ 
ural Experiment Station of the University of Tennessee, April, 
18S9. 
In this paper the author discusses the potato rot, caused by the 
fungus Phytophthora infestans, and a new disease, due to a nematode 
or thread-worm. After giving a detailed account of the habits of the 
former, the paper concludes with a chapter on treatment, which is 
briefly summed up as follows: 
Select for planting a light, sandy loam, or a soil which is well drained ; 
plant only perfectly sound or disinfected seed; spray the tops with the 
Bordeaux mixture* or some preparation containing sulphate of copper; 
store iu a cool dry place, and keep dry. 
The new disease was discovered among the potatoes obtained from 
the University farm, and is described as causing the tuber to wither, 
then dry up, and become hard. The skin is only partially discolored, 
but the surface is covered with small pimples, each surrounded by a 
depression. Sections through a diseased tuber revealed the fact that 
the flesh was apparently sound, but slightly wilted. The only dis¬ 
coloration of the flesh was immediately under the pimples; here the 
tissues were brown. Under the microscope it was seen that the brown 
areas were filled with numerous little worms of various sizes and in all 
stages of development. 
u These little worms,” says the author, u were at once recognized as 
nematodes or thread-worms, and were evidently the cause of the dis¬ 
ease.” 
u How did these worms get into the potatoes ? Probably from the 
soil in which they were grown, for it is known that many of the para¬ 
sitic nematodes spend a certain period of their existence under ground. 
It is very likely that they were first introduced into the University farm 
through planting infected seed. The potatoes planted were being saved 
for seed, and were these to be planted they would certainly carry the 
worms to the new crop and thus perpetuate the disease.” 
Owing to the limited knowledge of the life history of the nematode, 
the author says it is impossible to indicate any definite course of treat¬ 
ment. —B. T. Galloway. 
Siiipley, A. E., Cambridge, Englaud. On Macrosporium parasiticum . 
Annals of Botany, May, 1888. 
This is a note probably called forth by Kingo Miyabe’s paper which 
was reviewed iu the last number of The Journal. 
In 1887 the author was sent to the Bermuda Islands to study an on¬ 
ion disease prevalent among the onion plantations of the colony and 
supposed to be due to insect attacks. He found a fungous disease hav¬ 
ing two stages, the first caused by Peronospora Schleideniana , the second 
by Macrosporium parasiticum. 
* See Mr. Weed’s paper on page 158. 
