ОҒ PUCCINIA CORONATA, VAR. HIMALENSIS. 233 
(Exper. VIIL) I made only one experiment with a view to producing uredospore 
pustules with secidiospores. Оп the 1st August I placed a pot containing Brachypodium 
under some twigs of Rhamnus with ripe æcidia in а gardener's box, and on the 17th 
found the leaves covered with uredo pustules. 
From this aecount of my experimental inoculations, it will be observed that attaek by 
the sporidia of spores from Piptatherum and Festuca was in all cases less vigorous than 
with the spores from Brachypodium. From the beginning, after my first successful 
experiment, I had no doubt about the generic relationship between the Rhamnus æcidium 
and the teleutospores on Brachypodium ; but I felt less certain about the connection of 
the parasite on Piptatherum and Festuca. 
At first I feared that there might have been accidental contamination of my Pipta- 
therum and Festuca material with spores from Brachypodium, and this is the reason why 
the experiments with the former more numerous. My subsequent experiments convinced 
me that the fungus on Piptatherum and Festuca is really capable of producing the . 
secidium on Rhamnus. The difference in the vigour of attack is, however, noteworthy, 
and suggests the possibility that it may give rise more easily to some other secidium оп 
some other host. 
GENERAL REMARKS. 
Dr. P. Dietel, of Leipzig, to whom I sent specimens of the ecidium on Rhamnus 
and teleutospores оп Brachypodium, and to whom I am indebted for kindly criticism, 
informed me that both differed in habit from the European species. 1 could not myself 
detect any striking difference of habit in the ecidium (i. е. the form with short 
peridia) on comparing it with a specimen of the European Rhamnus scidium he sent 
me in return; but the specimen was small, aud I am not familiar with the appearance 
of the European form. The difference in habit of the teleutospore pustules on Brachy- 
podiwm is, however, very striking; and I have already alluded to the naked, small, 
circular, epiphyllous pustules, in contrast with the covered, linear, hypophyllous 
pustules at home. When I sent specimens of the teleutospore on Brachypodium to 
Dr. Dietel I did not know, and did not suspect, that the similar spores borne by Рір/а- 
therum and Festuca were biologically the same. Тһе habit of the fungus on these two 
hosts corresponds closely with that of Puccinia coronata in Europe, so far as I can make 
out from written descriptions. We have therefore here the interesting fact disclosed 
that such striking differences of habit need not be associated with specific differences. 
The interest of this discovery lies especially in its application to the rusts and mildews of 
cereal crops. Puccinia Graminis differs markedly from P. Rubigo-vera and P. coronata 
in the teleutospore pustules being naked, whilst in the latter they are covered; and 
Mr. T. J. Burrill writes of P. coronata, Corda :—“This species is certainly closely related to 
P. Rubigo-vera. Indeed it is scarcely possible to separate them, except by the terminal 
projections of the teleutospores in P. coronata, and these are present in varying degrees, 
sometimes nearly wanting.” * Тһе interest of this is very great both in the United States 
5 : an : и 
* Bulletin of the Illinois State Laboratory оѓ Natural History, vol. ii, art. 8, “Parasitic Fungi of Illinois,’ 
pt. i., 1885. 
