102 
great interest about which much might be written. We may 
recall, as a further example’ of this phenomenon, the cover-scales 
of the firs and of the western rina In these the cover 
scale is very leaf-like, especially, e. n Abies bracteata, and 
resembles more closely the lee ae than the fascicu- 
lated leaves, if we may judge by analogy with Pinus. In this 
genus, as in the larch, the cover scales are to be seen, without 
dissection, only in the young seed cones, as they are overtopped 
and finally quite hidden from sight by the more rapidly develop- 
ing seed scales. 
Francis E. Lioyp. 
ALABAMA POLYTECHNIC INSTITUTE. 
CONFERENCE NOTES. 
At the regular conference held April 5, Mr. F. D. Kern gave 
a further report on some of his recent work on Gymnosporangium, 
a genus of plant rusts. This genus of rusts is commonly 
as the cedar-apple rusts, since several species of the genus give 
rise to gall-like growths known as cedar-apples. 
e most rusts, those of this genus are, with one exception, 
foe cou. 4. e., have the different stages in their life cycles 
borne on different host plants. The life cycle of these rusts 
consists of two stages, the aecial and the telial, the former 
appearing, as a rule, on the members of the Apple Family and 
he latter on the cedar. One, however, is autoecious: 7. ¢., has 
both stages on the same host, the cedar. The aecial stage is 
not entirely limited to the Apple Family, one having been found 
on a member of the Rose Family and it is probable that others 
may also occur outside of the Apple Family 
Many rusts have in addition to the aecial and telial stages, a 
third stage, known as the uredinial or repeating stage. 
spores of this stage germinate immediately and by means of 
this stage the rust is enabled to spread over extensive areas in a 
unless the two kinds of host plants, apples and cedars, are grown 
