ee 23] [3 
ARY 3, 1923 
, but even here 1 imi is much larger than 
wo! “= Bite bosn expected, and is made to include 
fish, game, and productive insects, as well as the 
Y i aechisy and live-stock. The volumes are the 
ect descendant of the well-known Cyclopedia of 
ican Agriculture, which has run out of print and 
y reason of the cost will not be reprinted ix extenso. 
x —@) The plan of the volume dealing with crops is to 
rt with an account of the life processes of the plant, 
we ll written by W. J. V. Osterhout, followed by de- 
c of the effects of stimulation by artificial 
hi Sireak poisons, and electricity ; then to deal with 
and fungoid pests, and afterwards with plant 
weeding. The more technical part commences with 
accounts of the general principles of crop production 
d farm management, rotations, the growth of crops 
mder cover, etc., and finally comes the long list of 
d crops, each of which is dealt with in detail. 
_ More than a hundred experts have contributed to 
= volume and they have amassed a wealth of interest- 
material, much of which seems very strange to 
Inglish readers. How many agriculturists in this 
. untry are familiar with the agricultural process of 
ingeing the cholla’’? This operation is described 
n connexion with the cactus which constitutes a con- 
rable part of the vegetation in the southern part 
f the range country, New Mexico and Arizona. Un- 
rtunately the natural cacti are in the main spiny, 
d the attempts to introduce spineless forms useful 
9 stock have not proved particularly successful. 
thing daunted, however, the American ranger has 
ved equal to the situation ; by means of a gasoline 
ow-lamp the spines are singed off, with the result 
4t the cacti become much relished by live-stock and 
re literally devoured, the prickly pears being eaten 
early to the ground, while only the trunks and woody 
hes of the chollas (Opunta fulgida) remain. 
ing to agriculture proper, the most important 
most distinctive crop of the United States is 
aize, there always called “corn.” It is described as 
Mexican origin and related to Mexican grass teosinte 
ena Mexicana). The annual value of the crop 
eeds that of any other in the States, and is esti- 
tec at more than a billion dollars: the most im- 
tant individual States are Illinois, Iowa, Nebraska, 
issouri, Kansas, and Indiana; the least important 
e Montana and Wyoming. The yield varies from 
ss than ro bushels per acre in Florida to 35 or 36 
hels per acre in Connecticut, Massachusetts, Maine, 
pd Pennsylvania. Its different varieties are, to a 
reater extent than those of any other crop, capable of 
daptation to local conditions ; some mature in seventy 
eighty days, and are thus suited to the short seasons 
e North; these attain a height of 3 ft. or 4 ft. 
a NO. 2779, VOL. 111] 

































tions 
NATURE 
141 
only. Others found in the South have a growing 
season of six months, and may reach a height of 20 ft. 
or more, The crop fits well into rotation farming, and 
therefore is assured of a permanent place in agriculture, 
Another highly important crop is wheat, the 
area of which increased greatly in the States during 
the period in which it was shrinking here. Wheat is, 
however, essentially a pioneer crop, and it tends to 
shift towards the newer countries. Thus, during the 
past fifty years the centre of wheat production in the 
United States has moved westwards more rapidly than 
has the centre of the population. In 1850 New York 
was one of the great wheat-growing States ; now it 
produces only a little more than 1 per cent. of the 
United States crop. Later on, Southern Wisconsin 
and Northern Illinois became the chief wheat States ; 
now Kansas and North Dakota take the lead. Plant 
breeders and seedsmen have been busily occupied with 
the crop, and an immense number of different varieties 
have been grown: so far back as 1895 the U.S. De- 
partment grew more than tooo different sorts for 
several years, though a number were found to be 
identical, and only about 250 were of any value to 
American growers. Since then the varieties have 
increased considerably. 
Unlike Great Britain, the United States has a 
large area of spring-sown wheat, and, moreover, 
much of its wheat is grown under drier conditions 
than prevail here. There are still sections of the 
semi-arid country where no rotation is adopted 
and where wheat simply alternates with summer 
fallow, though, as Dr. Lyttleton Lyon points out, this 
will probably before long be replaced by a rotation 
including perennial grass or leguminous crops left 
down for some years. Elsewhere in the corn belt 
much of the spring wheat supply alternates with 
maize, though the winter wheat is usually grown in a 
rotation—maize, maize, oats, wheat, clover. This is 
somewhat of the same type as British wheat growing, 
with the substitution of wheat or oats for the first 
maize crop and roots for the second. The harvesting, 
however, is carried out altogether differently, and we 
have in this country nothing approaching the “‘ Header ”’ 
or the “ Combine ” now in use in parts of the States. 
As the book is written for American agriculturists 
there is no specific account of British crop production. 
There are, however, casual references, not all of which 
are accurate. Thus, it is stated that spurrey is culti- 
vated by dairy farmers in Great Britain, which we 
believe is not the case. 
(2) The volume on animals is equally rich in stores 
of interesting and valuable material. It is gratifying 
to a native of Great Britain to find how large a part 
is played by animals which originated here: horses, 
EJ 
