118 
NATURE 
| APRIL i, SBOms 


remaining relatively unchanged and destined to 
propagate the race. Recent investigations, to 
which the author has made valuable contributions, 
tend to show that the distinction, once established, 
is irrevocable, and that germ-cells are derived 
from pre-existing germ-cells in an unbroken 
stream—the germ-track. Modern methods have 
enabled investigators to trace the appearance of | 
germ-cells to earlier and earlier stages in develop- 
ment, thanks to certain distinctive characters of 
the cytoplasm or nucleus. The name keim-bahn 
determinants, or germ-track determinants, as we 
should prefer to call them, is given to such recog- 
nisable features in the cells. Although in some 
animals, such as Ascaris and Sagitta, the germ- 
cells have been traced back to the very early 
embryo consisting of only a few cells, the complete 
segregation of the germ-forming substance has not 
yet been observed in the first cleavage of the egg 
into two cells. 
Having given an excellent review of the evi- 
dence on this subject, Prof. Hegner proceeds to 
discuss the significance of the germ-track deter- 
minants, the chromosomes and mitochondria of 
germ-cells, the determinants of sex, and kindred 
questions. No doubt the most interesting problems 
relate to the possible identification of factors 
which determine the fate of cells—whether they 
will become germ-cells or body-cells, ova or 
spermatozoa, and also the fate of individuals— 
whether they will become males, females, or 
hermaphrodites. Through no fault of the author 
these problems are left unsolved. But concerning 
the germ-plasm theory itself he is confident that 
it rests on a firm basis, while inclined to believe 
that the germ-plasm resides not in the nucleus 
or chromosomes alone, but also in the cytoplasm. 
Quain’s Elements of Anatoniy. 
Wol-piva, Bart or 
Eleventh edition. 
Osteology and Arthrology. 
By Dr. T. H. Bryce. Pp. viii+329. (London: 
Longmans, Green and Co., 1915.) Price 
12s. 6d. net. 
In the latest (eleventh) edition of ‘‘Quain’s 
Anatomy ”-—a standard work—there have been 
several alterations, one of them being the inclu- 
sion of the chapters giving a descriptive account 
of the joints with the volume devoted to the 
skeleton of the human body. Part 1 of Vol. iv., 
which has just appeared under the. editorship of 
Prof. T. H. Bryce, thus gives a systematic 
account of the bones and joints of the human 
body. We are very glad to note that the editor 
gives a fairly full list of the more important of 
recent publications—an essential feature of a 
standard work. Prof. Bryce has done well in 
retaining the excellent drawings which Mr. D. 
Gunn, Dr. T. W. P. Lawrence, and Prof. G. D. 
Thane contributed to the last edition, and has 
improved the chapters dealing with the joints by 
the use of new coloured plates prepared by Mr. 
A. K. Maxwell. Another decided improvement 
is the introduction of an account of the develop- 
ment of the various parts of the skeleton in the 
chapters devoted to descriptions of the bones. 
NO. 2370, VOL. 95] 


} 

The investigations of Prof. Fawcett and of Dr. 
Alex. Low have been incorporated in the new 
text. Altogether, this volume of the new 
“Quain”’ will be welcomed by teachers and stu- 
dents of anatomy. 
LEREERS, TO THE, EDITOR: 
[The Editor does not hold himself responsible for 
Opinions expressed by his correspondents. Neither 
can he undertake to return, or to correspond with 
the writers of, rejected manuscripts intended for 
this or any other part of Naiure. No notice is 
taken of anonymous communications. ] 

The Rules of Zoological Nomenclature. 
As one of the British members on the International 
Commission for Zoological Nomenclature, I have fre- 
quently been asked where copies of the rules as 
revised and adopted at the Monaco Congress are to 
be obtained in separate form. May I therefore use 
your widely-read columns to inform zoologists (in- 
cluding paleontologists) that a translation into 
French, the official language, has been made by Prof. 
R. Blanchard, in agreement with the secretary to the 
Commission, and has been published in the Revue 
critique de Paléozoologie, edited by Mr. Maurice 
Cossmann, 110 Faubourg Poissonniére, Paris X? Re- 
prints may be purchased, at a price of 4s., from 
Messrs. Dulau and Co., Ltd., 37 Soho Square, Lon- 
don, W. Mr. Cossmann has added some useful notes, 
especially from the point of view of the palazontologist, 
but these, it should be remembered, have no authority 
} from the Congress or the Commission. 
F. A. Batmer. 
Natural History Museum, South Kensington, S.W., 
March 30. 

The Preparation of Anhydrous Solids. 
Tue following method may perhaps be of use to 
chemists and biologists who are concerned in the pre- 
paration of solid compounds in the anhydrous state 
for analysis, or in obtaining anhydrous tissues 
for moisture determinations, etc. It consists in 
utilising Prof. S. Young’s process for the purification 
| of alcohol from all water by distilling it through his 
| evaporator still-head, with the previous addition of a 
| suitable quantity of benzene. 
The tissue or compound to be dehydrated is placed 
in the distillation flask with alcohol and benzene in 
the proper proportions. When all the turbid ternary 
mixture of constant boiling point has been removed, 
by distillation from a water-bath, the remaining mix- 
ture of alcohol and benzene may be rapidly distilled 
away, and the last traces can be removed in a vacuum 
desiccator. By adjusting the quantities either alcohol 
or benzene can be obtained as the residual liquid, and 
the complete removal of either of them is far more 
readily effected than is that of water owing to their 
lower boiling points and greater volatility. 
The method avoids all risk of oxidation, a source of 
serious error when plant tissues are dried at 100° C. 
in air. It appears that this procedure can be adopted 
for quantitative determinations in many cases, and 
may .throw light upon the existence of water as 
‘““water of crystallisation” or as ‘“‘water of constitu- 
tion.” These points are at present being studied by 
Miss E. G. Wilson and the writer. 
W. R. G. ATKINS. 
University Chemical Laboratory, 
Trinity College, Dublin. 
