DopGE AND ADAMS: PERIDERMIUM CEREBRUM 257 
sometimes found to be adjacent to the nucleus. Occasionally two 
or three haustoria are found in the same cell. The cells of the 
cortex are not attacked by haustoria as frequently as are those 
of the phloém and medullary rays. Living hyphae with haustoria 
are found in wood tissue several years old. 
We were not fortunate enough to observe the exudation of 
spermatia in the New Jersey material. Sections of material 
showed the presence of spermatiophores bearing spermatia as 
early as March 25. They form a palisade layer that appears to 
be spread over indefinite areas of considerable extent like a caeoma 
type of fructification. This 
palisade is formed beneath four a tan TR " 
or more layers of newly devel- XN W ИІ Ар) NNUS 
oped cork cells. The spermati- NG С 05 УД Ар, i —»1 
4 
орһоге primordium consists of 
a compact mass of uninucleated 
cells of mycelium situated just 
above the outer row of cortical 
parenchyma cells. Below this 
the mycelium is sparingly de- Fic. т. Section through spermogonial 
veloped as compared with what primordium. €, cork; pl, plectenchyma; 
we find below the aecidium pri- же 
mordium. Тһе Virginia material was more favorable for the study 
of the spermatial layer. This material consists of the typical glo- 
boid swellings as described by most investigators of Р. Cerebrum. 
The galls are fairly smooth in appearance compared with the New 
Jersey material. The development of the palisade layer of sper- 
matiophores bearing spermatia was first observed in sections of 
material collected February 9. The primordium develops between 
the cortex and the cork layer as shown. іп TEXT-FIGURE I. The 
overlying cork layer is smooth in appearance. Specimens were 
placed in moist chambers and within twenty-four hours, exuda- 
tions of spermatia appeared. The cork becomes irregularly 
cracked so that tl tia exude in yellowish droplets. There is 
no special aperture thony the bark for the escape of the spermatia; 
they ooze out as sticky exudations through cracks naturally 
formed by the growth of the gall. On removing the overlying 
cork a yellowish crust-like layer of spermatiophores is exposed. 
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