Notes. 
560 
the usual period, and the crops become less regular ; the same effect 
is brought about during very cloudy and cold summers. 
6. The same conditions bring about sterilization of certain of the 
sexual cells. Thus, patches of cells within the antheridial sori fail 
to divide. Cells at the margins of female sori remain barren, so that 
the usually borderless sori acquire partial or even complete borders. 
7. There are strong reasons for concluding that the factor which 
determines the maturation and liberation of the sexual cells, and the 
fertilization of the oospheres, is the amount of the illumination to 
which the plants are subjected. 
8. The cytology of the reproductive cells will be described as far as 
it has been made out. 
University College, Bangor. J- LLOYD WILLIAMS. 
CHANGES IN THE GLAND-CELLS OF DROSERA PRO- 
DUCED BY VARIOUS FOOD-MATERIALS.— The work is an 
extension of that previously undertaken by the authoress, an account 
of which has already appeared in ‘ Quart. Micro. Journ./ vol. xxxix. 
In the experiments now described, leaves were fed with egg-albumin, 
globulin, peptone, fibrin, milk, nuclein, nucleic acid, and calcium 
phosphate, the histological changes in the gland-cells being noted in 
each case. 
The results to be described were obtained with fixing-fluids, widely 
differing in their chemical constitution. 
Egg-albumin. The basophil cytoplasm becomes pink, and is 
reduced in twenty to thirty hours to a mere vestige. After two days 
it commences to recuperate, and ultimately becomes again basophil. 
The changes in the nucleus comprise — (1) those of the nuclear chromo- 
somes, (2) those of the nuclear plasm, and (3) those of the nucleoli. 
In the resting-cell the nuclear chromatin is scanty, but immediately 
after feeding it commences to increase, till in twenty to thirty hours 
large segments are formed as in mitosis. During recuperation the 
segments again diminish. The eosinophil nucleoli are large in the 
resting-cell; they diminish after feeding in direct proportion to 
the increase of the basophil chromatin, and finally enlarge when the 
chromatin-segments diminish. 
Peptone is absorbed much more rapidly than egg- albumin, and 
produces in one hour changes similar to those effected by egg-albumin 
in twenty to thirty hours. 
