608 
German in its combination of trustworthiness in 
regard to detail, with almost complete absence of 
that wide “grip” which makes a work, or a 
worker, a living force in the development of the 
science. 
Chapter i. sketches the objects and general 
method of a course in practical embryology ; 
chapter ii., consisting of less than a page, is 
entitled “Embryology and  ‘ Entwicklungs- 
mechanik’”; chapter iii., about half a page in 
length, has the somewhat ambitious title, “ Evolu- 
tion, Epigenesis, Neo-evolution, Neo-epigenesis.” 
After this it is somewhat startling to find that 
chapter v., ‘“On some of the causal factors of de- 
velopment,” which teaches the student various ex- 
cellent Rouxian expressions in which his—and his 
teacher’s—ignorance may be safely wrapped up, 
extends over some eight pages. and 
and 
Many long 
Greek-looking words occur in this chapter, 
we confess to being not altogether convinced that 
they serve a useful purpose. We do not quite 
see of what special advantage it is to a German 
student—apart from some slight economy in time 
or ink—to refer to the wandering apart of cells 
which had come together as ‘‘Cytochorismus,” 
instead of using the expressive vernacular 
“Wiedervoneinanderlésung.” Technical terms 
are, of course, very necessary things, but there is 
often a danger—-and it is one from which _ bio- 
logical science is suffering greatly at the present 
time—that the affixing of a new technical name 
may be counted as explaining a natural pheno- 
menon, cr as making at least a definite step 
towards explanation. 
The first section of the book is completed by a 
short but good account of simple embryological 
technique suitable for elementary students, fol- 
lowed by a short sketch of developmental 
mechanics and a syllabus of work for a course in 
practical embryology. 
The second section of the book gives a good, 
though rather too short, general account of germ 
cells, early stages in development, and foetal mem- 
branes. The third section gives directions, illus- 
trated by outline drawings, for working through 
series of sections of various vertebrate embryos, 
while the concluding section of the book gives a 
short but good sketch of vertebrate organogeny. 
The book is excellently illustrated. It is too 
short, and it has, as we have indicated, other 
faults, but it is, on the whole, trustworthy, and 
will, we doubt not, serve its purpose to the stu- 
dent who hustles through a course in vertebrate 
embryology with the idea of picking up some 
knowledge of its methods rather than of becom- 
ing acquainted with its general principles as a 
branch of evolutionary science. 
(4) Vol. iv. of the ‘““George Crocker Studies in 
INO! 42 337, eaOlenoa | 
NATORE 
[AUGUST 13, 1914 
Cancer and Allied Subjects’ consists of a series 
of eight valuable memoirs upon the anatomy and 
development of the salivary glands of the mam- 
malia. Adult anatomy is dealt with by Carmalt 
(man, carnivora, ungulata, rodentia, insectivora, 
marsupialia) and Huntingdon (lower primates) ; 
embryonic development by Schulte (man, cat, 
pig); while the evolution of the primate salivary 
glands out of the presumably ancestral condition 
of a diffuse gland-field is discussed by Hunt- 
ingdon. Taken altogether the volume forms a 
valuable addition to our knowledge of the meor- 
phology of the salivary glands of the mammalia, 
and incidentally it affords a striking tribute to 
the wise and broad-minded administration of the 
George Crocker Research Fund of Columbia 
University. 
TROPICALE PRODUCTS. 
(1) The Cultivation of the Oil Palm. Some 
Essential Notes. By F. M. Milligan. Pp. 
xiv+1o00o. (London: Crosby Lockwood and 
Sonm,.1914.) Price 25.a0d- mer 
(2) Rubber: Its Sources, Cultivation, and Pre- 
paration. By Harold Brown. With a Preface by 
Dr. W. R. Dunstan. Pp. xiti+ 245+ xu plates. 
(London: John Murray, 1914.) Price 6s. net. 
(3) The Banana: Its Cultivation, Disiribution, and 
Commercial Uses. By W. Fawcett. With an 
Introduction by Sir Daniel Morris. Pp. xi+ 
287+plates. (London: Duckworth and Co., 
nQEge) Price 7s. 6da tiem 
HE trio of books under notice deal with 
three important tropical products, the first 
being chiefly associated with European colonies 
in western equatorial Africa, the other two being 
widely exploited. 
(1) The luxuriance and abundance of the oil-> 
palms in the coastal lands from Sierra Leone to 
the Cameroons furnish good evidence that the 
climate is particularly suitable and that the tree is 
well able to hold its own against plant and insect 
pests. The supply of fruit and nuts was origin- 
ally obtained from wild plants, but plantations 
have been formed by natives and are being ex- 
tended. Undoubtedly there is scope both for 
extended planting and for more careful cultivation. 
It is with the object of offering advice in these 
matters that Mr. Milligan has written his book. 
Unfortunately, although there are many allusions 
to his experience, the information given is ex- 
ceedingly meagre; on the subjects of seed-ger- 
mination, planting, and manuring, the advice is 
sound, but in other respects, notably as regards 
botanical details, the information is not only in- 
sufficient, but incorrect. The subject of oil-pro- 
duction is not included. 
