398 
tics have become so well determined and so 
familiar that if title pages were removed and 
all reference to the authors deleted, no as- 
tronomer could be left in doubt as to the 
source from which they came. 
Grorce C. Comstock 
UNIVERSITY OF WISCONSIN 
The Chemistry of Food and Nutrition. By 
Henry C. SHerMAN. Second edition. New 
York, The Macmillian Co. 1918. 
This well-known text-book has been re- 
written and presents modern knowledge upon 
the subject of nutrition in an exceptionally 
clear and readable form. The chemistry of 
foods is described, then the digestion and 
metabolism of the different food-stuffs. The 
review of the subject of the “vitamines ” and 
of “growth hormones” is excellently handled 
and nowhere have these “accessory factors” 
in nutrition been more clearly defined. Sher- 
man’s long experimental studies of the salt 
metabolism and especially the calcium metab- 
olism give authority to his discussion of the 
inorganic food-stuffs. The chapter on the 
dietary standards and economic use of food is 
of an order of excellence which has never 
been surpassed. Sherman’s experience, based 
upon his own painstaking researches into the 
dietary habits of the poor classes of New York 
City, conducted for the New York Association 
for Improving the Condition of the Poor, 
leads him to declare that “the most frequent 
deficiency in American dietaries is inadequacy 
of the total food or energy value and most 
dietaries actually observed are of such com- 
position as would furnish enough of each 
essential element if the total amount of food 
eaten were sufiicient to provide a liberal en- 
ergy supply.” 
Sherman clearly sets forth the principles of 
a sufficient and economical dietary in such a 
manner as to bring to mind the really great 
progress in the science of dietetics which has 
taken place in the last decade. This excellent 
and thoroughly scientific treatise upon nutri- 
tion should be in the hands of all who are 
‘interested in the food question, both as it 
appears now and as it will shape itself after 
SCIENCE 
[N. S. Vou. XLVIII. No. 1242 
the war. It is a pleasure to note that the 
author has been unusually conscientious and 
generous in giving credit to the work of 
others. Grauam Lusk 
SPECIAL ARTICLES 
THE FORMATION OF THE FAT DROPLETS IN 
THE CELLS OF TISSUE CULTURES 
Exprriments of Daddi (1896) and more par- 
ticularly those of Riddle (1910)? show that Su- 
dan III., fed to animals, is taken up by fat in 
the intestine, passes through the intestinal 
wall in combination with fat, and is deposited 
in the body cells in the form of red fat glob- 
ules. These observations suggested a method 
for testing out the question as to whether or 
not the mitochondria form the fat droplets. 
If Sudan III. remains attached to the fat, as 
Riddle seems convinced it does, and the cells 
store up this Sudan III. fat, the question 
arises, is the Sudan III. fat deposited in the 
mitochrondria before appearing as red fat 
globules in the cytoplasm? If such were the 
ease, we should be able to find traces of the 
Sudan III. in the mitochondrium, at least dur- 
ing the final stages in the formation of the 
fat droplet, but this could not be done, and as 
will be seen below, the mitochondria take no 
part in the formation of the fat droplet under 
such conditions. 
The yolk of a hen egg was mixed with 
Sudan ITI. until it beeame red. A small quan- 
tity of this red yolk was then diluted with 
Locke-Lewis solution and placed on a number 
of twenty-four-hour cultures of 6-9-day chick 
embryos (Lewis and Lewis method). Certain 
of the cells were then selected and their un- 
stained fat droplets noted ‘and drawn. Each 
of these cells was carefully followed for the 
next few hours, or until a number of fat drop- 
lets had appeared in the cytoplasm. These 
took the form of exceedingly small, reddish- 
yellow droplets, often far removed from any 
1Daddi, L., ‘‘ Nouvelle méthode pour colorer la 
graisse dans les tissues,’’ Arch. Ital. de Biol., 26, 
1896. 
2 Riddle, O., ‘‘Studies with Sudan IIT. in Meta- 
bolism and Inheritance,’’? Jour. Haper. Zool., 8, 
1910. 
