Diseased Potatoes. 
35 
of black dust, when the grain passes through the machine) 
inflammation of the mucous membrane, laboured action of 
chewing, flow of saliva, and occasional abortion have resulted. 
Fungi of the genera Puccinia and Ui'onij/ces, common 
enough on grasses, have caused similar symptoms though less 
in severity. Hay and straw containing these fungi are better 
not given to animals or at least with great care and precaution. 
Nothing but a microscopical examination can detect the presence 
of these injurious organisms. 
Uromyces Trifolii Wtr. and Erysiphe Martii Lev., two fungi 
attacking clover, are frequently present in clover hay. Hay badly 
infested by these fungi, causes, when eaten, “ blowing,” flow 
of saliva, and sometimes symptoms of a more serious character. 
The mildew fungus of grasses {Erysiphe Graminis D.C.) occurs 
also often in hay, and produces when present in abundance 
inflammation of the urinary, genital, and digestive organs, in 
some cases haematuria and abortion. 
In the case of giving potatoes, attacked by the fungus 
Phytophthora infestans De Bary, to animals, the question of the 
deterioration in the tuber is invariably involved. It has been 
found that the fungus itself causes no ill effect. The tubers, 
however, are known to decay rapidly from the action of 
putrefactive bacteria, and thus become dangerous as food, 
causing in this condition disturbances of digestion in the 
animals.' It has not yet been investigated what effect upon 
the animals is produced by the organisms causing “ bacterial 
rot” of swedes and turnips, but while these organisms may 
be harmless the quality of the roots is thus so reduced in 
its feeding value that they become quite useless. Scores of 
other fungi are known to produce similar loss of nutritive 
matter, for instance Phoma Betce Frank, occurring on mangolds, 
the still little known fungus described as “ potato canker 
fungus ” {(Edomyces leproides Trab.), the “ acid ” and “ dry ” rot 
of the potato,' &c. All these fungi produce through their action 
large quantities of butyric acid which has been stated to cause 
a decrease of the milk, or even inflammation of the stomach 
and intestines. 
The farmer need not unnecessarily be alarmed at these 
remarks as affecting the well-known practice of using small 
and even bad potatoes as “pig potatoes.” I am unwilling to 
commit myself to severe measures recommended by other 
' Quite recent feeding experiments with potatoes attacked by the Potato 
fungus and the acid rot bacterium have shown that when given in small 
quantities no ill effect was noticeable, but in larger quantities diarrhoea was 
produced in the experimental animals (pigs and cattle). Though these 
symptoms were not serious, it is also stated that the control animals put on 
much more readily fat than the others. {Kaiserl. Biolog. Anstalt f. Land 
und Forstwirtsc/iaft, Heft 4, February, 1907.) 
