BOOK REVIEWS. 
IQI 
The final result is excellently displayed on a map. 
The great main currents run in the tropics from east to west, 
being due to the rotation of the globe from west to east. Wherever 
there is an "open " space, the current rotates. Counter-currents and 
drifts occur in many places, according to the configuration of the 
land. An important one runs from west to east, all round the south 
of Australia, South America, and South Africa. 
Each chapter concludes with a useful summary ; chapters xiv. and 
xv. deal with " Differentiation " [Evolution] and Distribution of 
Plants. The author assumes the former existence of " primitive, 
world-ranging generalized types," the differentiation of which was " in 
response to the differentiations of their conditions." " Natural 
families seem to fall into two groups, the primitive and the derivative." 
But the author does not explain why some are primitive, nor what this 
word implies, especially as he includes the Compositae, which many 
botanists regard as the last family to have been evolved. He does 
not refer to the structure of flowers, upon which evolution so largely 
depends, but to the wide distribution. Again, he seems to think that the 
insectivorous families, Sarraceniaceae, Nepenthaceae, and Droseraceae 
are, on that account, allied ; whereas, according to Bentham and 
Hooker, they are situated widely apart, the similar structures having 
like causes only. 
In dealing with longitudinal distribution the author follows Gray 
and Dyer, considering that the Arctic regions supplied many plants 
which descended along certain longitudes, so that certain Japanese 
plants are allied to plants on the east side of North America ; such as 
the Ampelopsis species, and that other plants spread down the three 
continents to the south temperate zone. But there are many links 
between Australasia, the Cape, and South America, and it is more 
probable that the former Antarctic continent supplied a common 
source for certain species of Pelargonium, Adansonia, &c, for the 
sea-soundings reveal ridges extending to the three continents at 
a depth of 2,000 fathoms, while the sea is 3,000 fathoms between the 
continents. 
" The Carnation Year Book." Edited by J. S. Brunton. 8vo. 
68 pp. (Hortus Printing Co., Burnley, 1917.) is. 6d. 
It is inevitable that the Year Book of any Society should contain 
a considerable amount of material of more or less ephemeral interest, 
such, for example, as lists of prize-winners ; but, as has been done here, 
more permanent value may be given to such lists by noting the compo- 
sition of prize-winning groups and so on. In addition to these lists, 
and information relating to the Society, articles by its members add 
to the interest of this little book, which is the organ of the Perpetual 
Flowering Carnation Society, and particularly valuable is the list 
of Carnations registered by the Society with the raisers' names. 
