268 Reed . — A Study of the Enzyme-secreting Cells in the 
Korscheldt (’89) studied the gland-cells in the genital organs of 
Branchipus and in the glands of butterfly larvae. He found that the nuclei 
moved to the apex of the cells during active secretion and returned to the 
base during the resting period of the gland ; and concluded that the 
position of the nucleus in a cell indicates a participation in the activities 
at that place. In some cases where he thought that solid granules pass 
from the nucleus into the cell, there was apparently a direct change from 
nuclear substance into secretion, but he was not sure of the identity of the 
substances thus produced from the nucleus. During secretion, amoeboid 
movements were frequently observed in the nuclei. 
The results of Muller (’96), (’98) are very instructive, especially as to 
the extra-nuclear processes connected with the production of secretions. 
The first detailed cytological study of secreting-cells in the botanical 
realm was on the effect of stimulation of the glandular-cells of Drosera 
with egg-albumen by Miss Huie (’97), and a later paper (’99) by the same 
author on the effect of stimulation with substances of various composition. 
She found that the cytoplasm, which in the resting stage is abundant and 
stains blue with Mann’s Eosin-Toluidin blue, is exhausted by the process 
of secretion and shows strongest affinities for the red stain. During the 
period in which the secretion is being formed there is a constant increase in 
the amount of chromatin in the nucleus accompanied by a decrease in the 
size of the nucleolus. By the use of chemically different stimuli, very 
characteristic alterations are obtained in the morphology and colour- 
reactions of the cell. The cytoplasm is the cell-constituent most noticeably 
affected by external stimuli, but the nucleus is said to be the seat of 
metabolic activity. In all cases the process of recuperation begins in the 
nucleus. She concludes that the rate of plasmic changes depends on the 
rate of absorption, but that the rate of nuclear changes is commensurate 
only with the digestibility of the food. 
Rosenberg (’99) has given a very accurate and valuable description of 
the cytological changes accompanying the stimulation of the gland-cells of 
Drosera rotundifolia , making comparisons between the secreting-cells and 
the reproductive-cells of that plant. He gives the following interesting 
observations on the behaviour of the nucleus. The volume of the nucleus 
constantly grows smaller during secretion ; the chromatin shows a constant 
increase. At first the chromatin is in the form of granules on the nodes of 
the linin network throughout the nucleus. Gradually the granules collect 
at the nuclear membrane, where they fuse into longer or shorter rods ; finally, 
when the effect of the stimulus is particularly energetic, these rods unite and 
form a single thread with richly anastomosing branches. When the digestive 
process is ended the thread gradually becomes thinner, and here and there 
segments, until finally the original condition of the nucleus is reached. 
In certain cases where the leaf is very strongly stimulated and the feeding 
