1921] BRIEFER ARTICLES 153 
by green plants, and the transformation of proteins during seed germi- 
nation, to the investigation of tropisms and osmosis is familiar to all 
botanists. The influence of this work on osmosis extended beyond the 
botanical field into physics and chemistry. Of more general interest 
is his Handbuch der Pflanzenphysiologie, a notable reference text, the 
second edition of which was translated into English by Ewart. 
A sketch of PFEFFER’s scientific career has appeared in Science 
(51:291. 1920), so that I shall attempt to supplement this by the 
presentation of some personal traits. When known to the writer 
PFEFFER lived in the second story of the Botanical Institute in the 
University Botanical Garden. He was a tall man and spare, with 
black hair and beard, and with a pleasing and kindly face that imme- 
diately put one at ease in meeting him. The portrait accompanying 
this sketch makes him look more austere than was his wont, otherwise 
it represents him as he looked in 1892, at the age of 48. 
PFEFFER was a hard and continuous worker, and was rarely absent 
from the Institute, except for the four to six weeks’ vacation which he 
generally took with his family in August and September in Switzerland 
or on the Baltic. He arose at six in the morning, lectured at seven, 
worked in his own rooms until eleven, then made the rounds of his 
students’ tables, gave the noon hour to visitors, had luncheon, and 
worked again until five. From five to six he walked, and generally 
worked again in the evening. Besides keeping himself informed on the 
progress of science, especially physics and chemistry, he was always on 
the watch for new apparatus and new mechanical devices. Leipzig 
maintained a continuous mechanical and electrical exposition, and 
this Prrerrer frequently visited. He delighted in contemplating 
every new machine 
PFEFFER’ attitude toward his students was friendly and cordial. 
Regularly he visited the research laboratories at eleven, discussed with 
each man his problem, designed apparatus, and pointed out lines of 
experiment, frequently calling in the first assistant to receive direction 
for providing what the worker needed. If any student needed more 
time than could be given in the forenoon visit, the Professor would 
come again in the afternoon. The first assistant was always con- 
versant with the work of each student, and made the rounds forenoon 
and afternoon, besides always being on call when any help was needed. 
Each research man was given a key admitting him to the laboratory, 
and no restrictions were placed on his coming or going. Under PFEFFER’s 
rule work had to make progress. There was patience, but there was 
