426 
NATURE 
[Marcu 31, 1923 

ence,” is to be congratulated on his judicious selection 
of type and on the ingenious device whereby he refers 
in the index of names not only to the page but to the 
particular section of the page in which the name sought 
is to be found. 
The most generally useful part of the book, on the 
merits of which it will be judged, is part (r), and we 
have therefore examined some of the entries in this 
part, selected at random, in order to test its general 
accuracy. In such a work absolute accuracy is un- 
attainable, but the editor, aiming at a high standard, 
“thought it better not to publish any information 
except such as has been directly communicated by 
administrative chief officials. . . . He has further had 
the proof of each entry corrected by its contributor.” 
He has branded with an asterisk the rather numerous 
institutions which have failed to reply to his question- 
naires in time and has reproduced the notices of them 
which appeared in the 1920-21 issue : thirty-one institu- 
tions which have not replied since 1919 have been 
excluded altogether. This procedure unfortunately has 
not prevented what we cannot but regard as an excessive 
percentage of error in the entries tested. 
We venture to offer a suggestion regarding the entries 
in part (x) relating to institutions in the British Empire 
—about one-third of the total number. It is that the 
editor might use as the basis of such entries the Year- 
book issued by the Universities Bureau of the British 
Empire. Had he done so he would not have omitted 
such important institutions as the Osmania University 
of Hyderabad, Deccan, the University of Rangoon, the 
University of Patna (except for casual references), and 
University College, Swansea, his entries would have 
been more rather than less up-to-date, he would have 
saved himself a great deal of labour and expense, and 
would have been saved from such “ howlers ” as His 
Grace Eamon de Valera (Chancellor of the N.U.I.) and 
showing (and indexing) Petro Drilling as the name of a 
teacher instead of showing it as a subject (petroleum 
well-boring). 
There is, moreover, another and a very important 
side to the question. If our university administrative 
officials, after having supplied returns to their own 
Universities Bureau and to Government Departments, 
are to be plied with requests for the self-same informa- 
tion in different forms for international Indexes and 
the League of Nations (which now proposes itself to 
compile something of the kind), it will not be surprising 
if some of the answers are short or if the pages of the 
Index become even more abundantly starred than at 
present. If the universities of each country would 
combine to produce a national yearbook, these would 
make the best possible material for (if not constituent 
parts of) an Index Generalis. For the British Empire 
No. 2787, VoL, 111] 


the work is already done. Italy has her “ Annuario 
degli Istituti Scientifici””—not yet appearing annually, 
however. The American Council on Education is, in 
its recently formed Division of College and University 
Personnel, acquiring much of the requisite material for 
such a yearbook, and Switzerland and the Nether- 
lands have similar inter-university organisations. 

The Cactus Family. 
The Cactaceae; Descriptions and Illustrations of Plants 
of the Cactus family. By N. L. Britton and J. N. 
Rose. Vol. 3, pp. vii + 255, with 24 plates. 
(Washington: Carnegie Institution, 1922.) 
LL who grow Cacti will be glad to learn that 
the third volume of this fine work has been 
issued. It will probably appeal to a larger number of 
Cactus fanciers than the two preceding volumes, 
because it treats chiefly of the smaller kinds, which are 
more generally cultivated than the columnar or climb- 
ing species. This volume is of the same high standard 
of excellence as the two others, and as an account was 
given in Nature of July 7, 1921 (vol. 107, p. p. 580) of 
the general character, scope, and details of the work, 
it will be unnecessary to repeat them here. 
The subtribes dealt with in this volume are the 
Echinocereanz, consisting of 6 genera (3 of them new) 
and 115 species, the largest genera being Echinocereus, 
60 species, and Echinopsis, 28 species. The Echino- 
cactane consist of 28 genera (18 of them new) and 
166 species, the largest genera being Ferocactus, 30 
species, Malacocarpus, 29 species, Gymnocalycium, — 
23 species, and Echinofossulocactus, 22 species. 
The Cactane consist of the two genera Discocactus, — 
7 species, and Cactus (better known .as Melocactus), 
18 species. Altogether 36 genera (of which 17 are 
monotypic and 21 are new) and 306 species are de- 
scribed, and well illustrated by 250 figures in the text, 
and 24 plates, most of them coloured. 
. Most of the Echinocactane are known to cultivators — 
as belonging to the genus Echinocactus, and they will 
perhaps find it difficult to understand why, in this 
volume, only 9 species are placed under that genus, — 
and all the others relegated to other genera. The 
reason is that while the vegetative characters of a 
large number of species is similar in type, the structural - 
and these floral differences 4 
have, in this work, been utilised for generic distinction — 
All this is made q 
details of their flowers differ, an 
in a manner not practised before. 
manifest in the keys, which are concise and clear, so 
that with the aid of the very numerous illustrations — 
few should find difficulty in referring an unnamed — 
species of the group to its proper genus. 

oleae re: 
