Gelehrte Gesellschaften. 
429 
Berichte gelehrter Gesellschaften. 
American Academy of arts and Sciences. 
Sitzung vom 8. Dezember 1886, 
Herr Roland Tkaxtcr sprach: 
On certain cultures of Oyrnnosporaiigium, witli notes on their 
Roesteliae. 
In a paper entitled “Notes on some Species of Gymnosporangium 
and Chrysomyxa of the United States,“ communicated to the Academy 
in February, 1885, Prof. Farlow gave an account of certain cultures 
conducted by him with a view to determine the relation of the species 
of Gymnosporangium found in this vicinity to the different Eoes- 
teliae growing in the same locality; and it is the object of the present 
paper to Supplement these observations by an account of further experi- 
ments on the subject undertaken by the writer while studying in Prof. 
Farlow’ s laboratory during the past spring. 
The more important results obtained have already been published 
in an article read by Prof. Farlow before the American Association 
for the Advancement of Science, at Buffalo, and contained in the Sep- 
tember number of the Botanical Gazette; yet a somewhat more detailed 
account may be of interest, together with some further observations 
on the species of Roestelia which may serve to explain several 
doubtful points in this connection. As a guide also tho those unac- 
quainted with the cycle of development of these fungi, it may not be 
amiss, before considering the cultures, briefly to summarize it. 
The species of Gy mn o s p or an gia, or cedar apples as they are 
popularly known, are fungi parasitic upon certain cedars, — in this 
vicinity Juniperus communis and Virginia na together with 
Cupressus thyoides being the species attacked, — upon which 
they produce distortions more or less characteristic in appearance. At 
maturity, towards the close of spring, the fungus consists of certain 
sporiferous masses emerging from the distortions produced by the 
growth of its mycelium in the stem or leaves of the host plant. When 
moistened, these masses expand to many times their formcr size, be- 
coming soft and gelatinous, while the spores upon their surface ger- 
minate with great rapidity. This germination consists in the growth 
of certain hyphac (p r o m y c e 1 i a), which in turn bear laterally one or 
more, usually four, secondary spores, known as sporidia; or simply 
break up by the formation of transverse partitions into spore-like bodies 
having a similar function. These sporidia are then carried by the 
wind, often very considerable distances, until they come in contact 
with certain Pomeae which furnish conditions for the further develop- 
ment of the fungus. In case these conditions are not supplied, the 
