85 
Ingvar Jorgensen and Walter Stiles . 
genial job, it was up to him to make good in it. He certainly did 
make good. His brains and his underlying grit told, for all that he 
was a peace-loving student by nature and inclination. Though far 
from being “ typically English ” in mentality and tastes, he had 
some of the best English qualities—modesty, reticence, humour, 
pluck, and gaiety under trying conditions. One of his friends says 
that during the training, Marsh gave him the impression of acting 
from a sense of duty and of never being really keen on the work, 
though he did not confess anything of the kind. It may have been 
so : he did not give me that impression, but simply that of a man 
who put all of himself, as a man should, into the job he had taken 
up. His humour stood him in very good stead. “He was so 
cheerful—everything was always a joke ” writes one of his brother 
officers. He evidently had a real hold on his fellows in the army. 
“ I’ve never known a captain so much liked by his men ” says one : 
“ Nearly all the men spoke of him in their letters ” written just 
after his death. And his servant wrote: “ He was not only 
respected, but loved.” He had the same hold on those who knew 
him well at Cambridge, and, quite apart from his scientific promise, 
his loss is very bitter to those who loved him. 
A.G.T. 
CARBON ASSIMILATION. 
A Review of Recent Work on the Pigments of the 
Green Leaf and the Processes connected with them. 
By Ingvar Jorgensen and Walter Stiles. 
(Continued from p. 23). 
P. Variations in the Quantity of the Leaf Pigments in 
Different Plants and under Different Conditions. 
✓ 
The part of Willstatter’s work with which we have dealt so far 
concerns the characteristics of the pigments, their chemistry, and 
the methods for extracting them. Willstatter has further devised 
methods for the quantitative extraction and separation of the four 
pigments. Here, as in the aspects of the leaf pigments we have 
already considered, we are in the fortunate position of being able to 
neglect all earlier work on the subject, for it is now obvious that 
the methods employed by workers before Willstatter are imperfect 
and must give erroneous results. Thus, for instance, it is essential 
to separate the green and yellow pigments in order to obtain 
quantitative data as to the amount of chlorophyll present; and 
again other substances liable to be extracted with the pigments, 
