116 
namely, (a) the willing agreement among all 
technical writers to use the word weight to 
designate the earth pull on a body, followed by 
(6) a careless reversion to the usage of the 
coal man and the acceptance of his meaning 
when he sends a bill for 2,000 pounds weight 
of coal! ‘Let it be understood that the coal 
man’s weight is precisely the physicist’s and 
the chemist’s mass. The balance scale meas- 
ures mass, it does not and can not measure 
force in any precise sense until the ratio of the 
local value of gravity to the value of gravity 
in London is known. Wm. S. FRANKLIN, 
Barry MacNuttr 
THE CANONS OF COMPARATIVE ANATOMY 
In a recent number of Scrence! Professor 
W. P. Thompson refers to a recent letter of 
mine to that journal. He maintains that the 
assertion on my part that he made use of the 
Canons of Comparative Anatomy through 
ignorance to reach an erroneous conclusion is 
‘inaccurate. This seems to be contrary to the 
facts, since Professor Thompson on his own 
showing is culpable either of inexcusable igno- 
rance or deliberate misrepresentation. He 
emphasizes the value of the genus Vaccinium 
as a type illustrative of the relations between 
two main forms of vessel in the angiosperms, 
namely, the one with scalariform perforations 
and that with porous perforations. Had his 
acquaintance with the anatomy of Vaccinium 
been more complete, he would have realized 
that the type of vessel found in the Gnetalian 
genus Ephedra is also present there. Contrary 
to Mr. Thompson’s statement, moreover, ves- 
sels of the Gnetum type prevail in the higher 
angiosperms rather than in the lower ones, 
being universal, for example, in the Composite 
and extremely common in the monocotyledons. 
It is unfortunate that Professor Thompson 
either through ignorance or intention has 
failed to emphasize the presence of the Gnetum 
type of vessel in the angiosperms, particularly 
as In many cases it has in that large group a 
mode of origin similar to that described by 
him in the case of Gnetum. It thus appears 
1N. §., Vol. XLVIL, No. 1221. 
SCIENCE 
[N. S. Von. XLVIII. No. 1231 
that his contention that the Gnetum and 
Ephedra types of vessels are fundamentally 
different in origin from those of the angio- 
sperms is without foundation in fact, since 
both these types are actually present in quite 
high angiosperms. Professor Thompson’s at- 
titude is further highly inconsistent, since in 
earlier publication he has called attention to 
the resemblances between the wood rays of 
Ephedra and those of certain angiosperms, and 
to the occurrence of nuclear fusions in Gnetum 
which he compares with that found in the case 
of the endosperm nucleus of the angiosperms. 
E. C. JEFPRrey . 
WHOLE-WHEAT BREAD 
To THE Epitor or Science: As a contri- 
bution to the discussion “Shall We Hat 
Whole-wheat Bread,” may I quote from the 
findings of a special committee appointed by 
the Royal Society of England, to study this 
matter,” as follows: 
The bread now in use is prepared from grain 
milled to 90 per cent. with the addition of other 
cereals. After investigation, a committee of the 
Royal Society has issued a report on the following 
questions: (1) What gain, if any, in food value 
accrues from a rise in the milling standard from 
80 to 90 per cent., and does the dilution of wheat 
flour with other cereals modify the food value of 
the bread? (2) What would be the effect on the 
health of the consumption of such breads? (3) 
How far would such breads prove acceptable? Hx- 
periments were made with wheat flour, extracted 
to 80 and to 90 per cent. The analytical work was 
done in the biochemical department of the Univer- 
sity of Cambridge and in the physiological labora- 
tories of the universities of Glaszow and London. 
The diet consisted of 800 gm. of bread with but- 
ter, cheese, minced or potted meat, fruit jelly, milk 
and sugar, tea or coffee, and in one case beer was 
taken as a beverage. This dietary yielded about 
3,680 calories a day. The effects were remarkably 
uniform.s Bread made from the 80 per cent. flour 
yielded for nutrition 96.1 per cent. of the energy 
contained in the diet; bread made from 90 per 
1‘‘The Conservation of Wheat,’’ Sciencz, Vol. 
XLVII., No. 1218, p. 429; Scrzenon, N. S., Vol. 
XLVII., No. 1210, p. 228, March 8, 1918. 
2 Copied from the J. Amer. Med. Assn., Vol. 70, 
No. 22, p. 1619, June 1, 1918. 
3 The italics are my own. 
