260 SEMI-CENTENNIAL OF TORREY BOTANICAL CLUB 
which the primordium is developed. Only two rows of overlying 
cortical parenchyma cells are shown in this section. The number, 
however, varies and there may be as many as four or five layers. 
Above these outer parenchyma cells (cp) there are from one to 
four layers of flat, thin-walled cells (c) and beyond these one to 
four layers of large sclerenchyma cells (s). At the base of the 
primordium there is a compact mass of interwoven hyphae (5) 
from which parallel rows of cells originate. These are the gameto- 
phoric hyphae (g) which are eight or more cells in length. The 
fusion cells (f) in these chains are recognized by their being deeply 
stained in the preparations. Beyond the gametophoric hyphae, in 
this stage, we find a considerable development of pseudoparen- 
chyma (р). Above the pseudoparenchyma the vegetative hyphae 
(v) are shown pushing in between the cells of the outer layers of 
cortical parenchyma (cp). The aecidium has its origin slightly 
deeper than the spermogonium. In the spring of 1916 at Lake- 
hurst, N. J., the matured aecidia were first observed on May 21. 
In no instance have we discovered spermogonia and aecidia 
following each other on identical areas of the same gall. 
Certain galls were found developing only aecidia, others only 
spermatia. In the Virginia material it was found in several 
instances that both developed on different parts of the same 
gall. This would indicate there is an alternation of the 
aecidium and spermogonium as reported by Hedgcock and 
Long* and others. In the large canker-like swellings of 
the New Jersey material we have not found galls bearing 
both aecidiospore and spermatia galls. We have found a few 
cases of infection on P. rigida in New Jersey with the swellings 
still bearing the rough, scaly bark showing plainly aecidial scars 
in April. When this was removed we found directly beneath, 
separated from it by a few layers of new cork, aecidium primordia. 
This may have been due to the possibility that the old cork 
layers were not shed the previous year, that is, at the time 
spermatia were developed. 
Seedling oaks of Quercus ilicifolia and Q. marilandica were 
found near Lakehurst, New Jersey, with mature uredosori as early 
* Hedgcock, G. G., & Long, W. H. Identity of Peridermium fusiforme with 
Peridermium Cerebrum. Jour. Agr. Research 2: 247—249. 1914. 
