6 
H. H. RUSBY. 
view to the detection of known poisonous plants, but with¬ 
out success. He had studied his cases very thoroughly and 
was able to give a perfect account of the symptoms, upon 
which I expressed the opinion that no native plant other 
than some species of fungus could have been responsible for 
the results described. Subsequent observation revealed the 
fact that golden-rods were abundant in the pasture and that 
these were thickly infested with parasitic fungi. It was 
further observed that these were eaten by the horses, and it 
is my recollection that Dr. Helmer stated that the affected 
animals exhibited a morbid appetite for the plant, not ob¬ 
served in those which were healthy. 
The specimens were submitted to Prof. Byron D. Hal- 
sted for determination, and he reported the principal fungus 
to be Coleosporium solidaginus, Thum. Many of the sori of this 
were in turn infested with a second species, Darliicci filum y 
Cast. Neither Prof. Halsted nor other mycologists to whom 
I submitted the query were aware of any poisonous record 
having been made by either of these fungi. Nevertheless, in 
view of the full report furnished by Dr. Helmer, and of the 
very thorough manner in which he had investigated the sub¬ 
ject, I had no hesitation in pronouncing one or both of them 
to have been the probable poisoning agent. 
Dr. Helmer subsequently performed some experiments 
upon rabbits and dogs, injecting subcutaneously an infusion 
of the Coleosporium, as well as he could separate it from the 
tissues of the host-plants. The results were distinctly poison¬ 
ous, and fatal in all cases wherein rabbits were the subjects. 
The symptoms presented points of similarity to those ob¬ 
served in the poisoned horses. As these experiments were 
not carried out under the customary precautions and control 
conditions of the physiological laboratory, I could not fully 
endorse any conclusions deduced from the results. Never¬ 
theless they were of great interest, and it is to be hoped that 
Dr. Helmer will yet publish them. 
The conclusions reached from these cases were not re¬ 
garded as sufficiently positive to warrant publication, but in 
view of the fact that since then various independent observ- 
