380 BOTANICAL GAZETTE [MAY 
In the diseased area the cuticle and the epidermal cells are 
affected to a greater distance from the center of infection than the 
sponge cells. They are early turned brown and the epidermis is 
shrunken. The sponge tissue is badly disorganized, but chloro- 
plasts and nuclei are present. The latter attain a larger size, and 
have a light brown color, whereas when normal they are easily 
stained with hematoxylin. They often have two nuclei and a 
granular plasm. Later, in the degeneration of the nucleus, the 
nucleoli disappear and the nucleus stains deeper. The chloro- 
plasts may later disappear and afterward the other constituents of 
the cell. Fig. 8 shows the light 
brown enlarged nuclei in cells 
affected by the parasite. 
g. CASTANEA DENTATA 
(Marsh.) Borkh., parasitized 
by Cryptosporium epiphyllum 
C. and E.—The normal leaf is 
covered by an epidermis with 
cells rather larger than those of 
the sponge tissue. The pali- 
_Fic. 8.—Two cells from a leaf of sade tissue, which is composed 
Smilacina racemosa parasitized by Phyllos- 
ticta cruenta, showing enlarged nuclei. of very long narrow cells, some- 
times with a row of short cells 
below, occupies about half of the total thickness of the leaf. The 
sponge is very loose and has large air chambers. The cells of the 
lower epidermis are smaller than those of the upper. 
As examined in prepared material, the diseased area is very 
sharply. separated from the healthy part of the leaf. There are 
practically no cells that show transition phases between the normal 
and the diseased conditions. The epidermal cells over the para- 
sitized portion are flattened, and often filled with granular deposits 
which have also been noticed in other diseased plants. The 
palisade and sponge cells are much shrunken and the entire ‘con- 
tents were killed apparently before the specimen was collected. 
The entire diseased area is yellow-brown, while the normal tissue 
stains easily with anilin blue. No cytologic changes are to be 
seen except the deposit of the yellow-brown material throughout 
