320 The N.Z. Journal of Science and Technology. [Jan. 
While the general conception and detail of the book are alike excellent 
for the beginner, the more advanced student will note some omissions of 
considerable importance. For example, in dealing with the problem of 
wing-growth, no mention is made of the turning-over of the wing-buds 
in Odonata and certain Orthoptera, in which the hindwing-sheath comes 
to overlie that of the forewing. In dealing with the evolution of the pupal 
state (chapter ii) the author passes in review the various larval forms found 
in the Hymenoptera, but quite fails to mention the praepupal or subpupal 
stage, which is the most significant of all facts in connection with this 
problem, and so misses the clue to the explanation of the reduction of the 
number of instars, without which a true view of the meaning of the pupal 
state can scarcely be attained. Again, much has been written in late 
years on the internal changes accompanying the metamorphosis, yet this 
fascinating and intricate subject is dismissed in ten pages at the end of 
chapter iv. There are many students of insects at the present day who 
would be extremely grateful for a clear exposition of the stages by which 
the “ imaginal buds ” of Weismann, as seen in the dipterous maggot, have 
been evolved, and for an authoritative account of the definite changes 
undergone by the various internal organs and tissues of the insect-body 
during the actual metamorphosis. Though it is realized that these are diffi¬ 
cult subjects, and that more researches upon the older Holometabola are 
still needed, it is somewhat disappointing that so little help in elucidating 
these problems is offered in the present volume. 
The text and figures have been, on the whole, very carefully prepared, 
though there are a few errors that need to be corrected. On p. 16, fig. 7, 
the letters A, C, M are made to point to the wrong veins. On p. 106 it 
is stated that “ the ninth segment has a pair of stiff, bristly cerci ” : the 
accepted definition of “ cerci ” makes this statement inaccurate. On p. 178 
it is noted that, in the order Orthoptera, “ the female’s ovipositor is well 
and typically developed ” : but this is certainly not true of the cockroaches 
and mantids, included in the order. On pp. 178-9 the definitions of 
the orders Plecoptera and Isoptera leave much to be desired, while the 
Embioptera, or web-spinners, are entirely omitted. A stereotyped error, due 
to Alvah Peterson and others, is perpetuated on p. 185, where it is stated 
that “labial palps are absent” in the Diptera : the latest researches go 
to show undoubtedly that the labellum is formed from these palps. On 
p. 269 it is stated that the Coleoptera of the Trias include representatives 
of the Chrysomelidae and weevils. This is incorrect: the only families 
which can be shown to have existed with any certainty at that time are 
the Oupesidae and Hydrophilidae, though there is a strong probability that 
other elytra belonged to the Carabidae, Tenebrionidae, and Cerambycidae, 
together with a few more obscure archaic families. 
The author is to be congratulated on this his latest work, which is to be 
strongly recommended to all students who are interested in this fascinating 
subject. 
R. J. T. 
