94 MR. C. B. PLOWRIGHT ON CERTAIN 
lead us to suppose. From the frequency with which (Ersted's 
experiments have been repeated by continental botanists, it was 
remarkable that the above facts had not been already made 
known ; and it became necessary, before the results of my experi- 
ments were published, that they should be confirmed by 4 
considerable number of observations. Since 1881 some 90 
experimental cultures have been made with these Fungi, so that it 
cannot be alleged that my conclusions have been hurriedly made 
upon insufficient data. During the year 1882 Rathay * published 
the results of a series of cultures made by him with the Gymno- 
sporangia, which are subjoined in a tabular form. It will be seen 
at a glance that these Uredines have their »cidiospores upon & 
number of host-plants, and that the original statements of (Ersted 
concerning them require a certain amount of modification. 
Rathay's Experimental Cultures with the Gymnosporangia. 
Positive Results. 
à Teleutospores. ZEcidiospores on 
ymnosporangium fuscum, DC, ............... eee is. 
(Tremella Sabine, Dicks.) PJAuceparia. E 
à SU g P. Aria. 
ymnosporangium juniperinum, Fr. ..................se. Amelanchier vulgaris. 
(Tremella juniperina, L.) Pyrus Malus. 
P. vulgaris. 
P. torminalis. 
Gymnosporangium clavariseforme, DC. .................. P. communis. 
(Tremella clavarieformis, Jacq.) Crataegus Oxyacantha. 
C. monogyna. 
Negative Results. 
( Mespilus germanica. 
CrategusOxyacantha. 
Gymnosporangium fuscum, DC. ............... ese C. monogyna. 
"* 5 Pyrus Malus. 
P. Aria. 
P. torminalis. 
Mespilus germanioa. 
ium iuni i isOxyacantha. 
Gymnosporangium juniperinum, Fr. .................. - pii en 
Pyrus domestica. 
P. torminalis. 
Mespilus germanica. 
Gymnosporangium clavarixforme, DC. ............ Pyrus Malus. 
"t ] P. domestica. 
P. Aria. 
ven which it appears that Rathay was unable io discover 
which of the Gymnosporangia produced the Restelia on Mespilus 
Mian nnne BR Spermogonien der Rostpilze,’ Wien, 
