REVIEWS AND EXCHANGES 
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Entomology, with Special Reference to its Biological and Economic Aspects. 
By Justus Watson Folsom. 6 inches x 9 inches, 485 pages, 5 plates and 300 
text figures. Rebman, Ltd. Price 14s. net. 
The aim of this book is to give a comprehensive and concise account of insects, 
in order to meet the growing demand for a biological treatment of entomology, 
which often does not rise beyond collecting and cabinets. The volume, though 
planned primarily for the student, is intended also for the general reader, and it 
takes but a glance at the pages to appreciate that the author has been successful 
in his endeavour. Besides the necessary figures dealing with structure, we find a 
wealth of interesting pictures, such as those showing the changes of the caterpillar 
into the chrysalis and the developing wings of an emerging butterfly. Others, 
again, illustrate curious habits on the part of insects, mimicry, the relations of 
insects with plants, and many questions which one does not usually find in books 
dealing with classification. Similarly in the letter-press, all sorts of topics of 
general interest are discussed, for instance : — economic entomology, the relations 
of insects, the conveyance by insects of diseases that affect human beings, and 
a consideration of those species which form the food of birds. The extreme 
intricacy of the subject is well brought out, when it is shown that if a bird destroys 
a parasitic or predaceous insect it is not necessarily inimical to human interests, 
for the insect might happen to attack other insects which lived on noxious plants 
or those of no economic value. The chapter dealing with the origin of adapta- 
tions and of species, gives a very interesting and valuable resume of the theories 
of Darwin, Romanes, Weissman and de Vries, so that there is food for the general 
student as well as for the specialist. Finally, more than seventy pages are devoted 
to the literature of entomology, and those selected contributions which contain 
special bibliographies are marked accordingly. 
The Evolution of Man, a Popular Scientific Study. By Ernst Haeckel. 6 
inches x 8jj inches. 2 volumes in one. 364 pp. , 408 figures. Watts and 
Co. Price 2s. net. 
This is a condensed translation, by Mr. Joseph McCabe, of the fifth and 
enlarged edition of Haeckel’s celebrated book. It is one with which every man 
and woman with any claim to culture, or the slightest interest in themselves, 
should be familiar. Of course, there are those to whom the idea that they are in 
any way connected with the “lower animals” is repugnant, but there are many 
to whom the truth is unpalatable. The first volume is occupied with the history 
of individual man or ontogeny, and although the embryology of a number of 
simple creatures is carefully described, it will require clo-e attention on the part 
of those who have no previous knowledge of zoology in order to master the 
intricacies of the subject. The translator has, however, done his best, in his pre- 
face, to help the general reader, and the arguments in the second volume in 
which the racial hi-tory or phylogeny of man is discussed, are more easy to 
follow. There area few points which even the biologist would like made a little 
more clear ; on page 1 15, lor instance, the permanence of mammary glands (once 
only found in the female, and by heredity communicated to the males), in 
both sexes of the higher mammals and man, is given as “a fine instance of the 
much disputed ‘ inheritance of acquired characters.’ ” In the usually accepted 
sense, “ acquired characters ” are those gained by the individual during its own 
lifetime, and with regard to the inheritance of which there is practically no 
reliable evidence. The chapter on our various predecessors— protist, worm-like, 
fish-like, with five toes, and ape-like — should prove of particular interest, and 
these are practically what any modern zoologist would enumerate. Discussion 
would probably cenire round the ancestors immediately preceding the vertebrate 
type as foreshadowed by the simple and skull-less lancelet. Haeckel gives his 
own views, as will be evident in the chapter on worm-like ancestors. It has been 
found that the blood of one kind of animal will in the veins of another act as 
poison, unless the two are very closely related. In the chapters on ape 
ancestors, some remarkable experiments are mentioned which show that while 
human blood is huriful to the lower monkeys, it has no effect when transfused 
into the anthropoid apes. 
