ie 
1897 | BRIEFER ARTICLES 43 
represented by Dixon in P. sé/vestris. Nearest the tip are the two 
sterile nuclei {c), that of the stalk-cell and that of the tube, which have 
lost their original outline and evidently have begun to disintegrate. 
Behind them are the male cells (a and B), usually much more deeply 
stained than the sterile nuclei, and with B slightly darker than a. The 
protoplasm about the nuclei contains numerous starch grains, stained 
red by the erythrosin, as are the two sterile nuclei, and appearing in 
sharp contrast with the generative nuclei and the wall of the tube, 
stained blue by cyanin. 
figure 6 is contributed by Mr. W. D. Merrell, and represents a 
pollen-tube of Taxus baccata, which shows an interesting deviation 
from the description given by Belajeff. The tube has reached and 
spread out over the top of the endosperm region, in which an arche- 
gonium is seen. At an unusual distance up the tube is the large 
generative cell, not yet divided into the large and small male cells. 
Above the generative cell lie the consorting stalk-cell nucleus and tube 
nucleus, whose position is described as invariably in advance of the 
generative cell. In fact the tube nucleus is normally in advance of 
the generative cell, and the stalk-cell nucleus soon passes it. Belajeff 
states that at the very tip of the tube the generative cell divides, and 
the larger male cells pass into the oosphere, leaving the smaller male 
cell and the sterile nuclei, now more or less disorganized, stranded in 
the tube. The preparation figured would indicate that the generative 
cell sometimes passes in front of the sterile nuclei at an earlier stage 
than noted by Belajeff. In 6a the general relation of parts is indi- 
cated in outline. se psn M. CoutTer, a of Chicago. 
MYRIOSTOMA COLIFORME. . . 
Avcust the 28th, > while 0 on an excursion t Albino Beach, . 
