2096 SOME NEW BOOKS [ocTroBER 
Beginning his researches during the previous decade he at first proceeded slowly. 
The literature of the subject was difficult to obtain, and when obtained threw 
little light on the almost unknown coccid fauna of Ceylon. But Mr. Green, 
not discouraged, resolved to study every species de novo, whether described or 
not; acquiring his knowledge first-hand from nature, as though he might be 
Adam in the Garden of Eden. This method, in the hands of an intelligent 
worker, is sure to be successful, and it was eminently so in the case of Mr. 
Green. He not only prepared descriptions, but also elaborate drawings of 
every species in all its stages, so far as they could be obtained. This done, a 
thorough examination of the various publications on Coccidae had to be made 
before the apparently new forms could be reported as such; but this revealed 
comparatively few identities. In Part I. there are thirty species described, of 
which seventeen were new; in Part II. are twenty-nine species, all but three 
discovered by the author. It often happens, on receiving a paper describing so 
many new species, that one can immediately detect some synonymy ; but I do 
not know of any “‘bad species” among the forty-three above mentioned, and 
doubt if there are any. The descriptions are good, and the plates most 
beautiful. There is an introductory portion on the general principles of 
coccidology, including a new classification of the sub-families and full directions 
for collecting and preserving material. There is also a chapter on the insecti- 
cides and other means for destroying Coccidae which injure cultivated plants. 
In the last-mentioned chapter the interesting fact is brought out that practically 
all the injurious coccids in Ceylon are those described from elsewhere and 
presumably introduced into the island. The truly native species, almost 
without exception, have proved to possess no economic importance ; though of 
course these very species, carved somewhere e/se, may yet become notorious. 
An unfortunate conservation, as it seems to the present writer, is shown in 
regard to genera. The species assigned to Aspzdvotus represent at least five 
very distinct groups, which are at least of sub-generic value. Aonzdza is made 
to include very diverse forms, including three distinct generic types. Similarly 
the twenty-six species assigned to Chionaspis are by no means truly congeneric ; 
for instance the first six, asprdistrae, theae, albizziae, mussaendae, rhododendri, and 
scrobicularum, belong properly to Hemichionaspis. The generic classification of 
the Coccidae, however, is at present in a transitional state, and an author cannot 
be blamed if he hesitates to propose changes while yet uncertain what those 
changes should be. 
Simply as an illustration of good methods this work ought to be examined 
by zoologists who do not expect to study Coccidae ; while for the coccidologist 
it is of course essential. Under these circumstances it is to be regretted that the 
manner of publication is such as to make it extremely costly. The only edition 
has coloured plates, which of course are expensive, while the colouring does 
not greatly add to their value for scientific purposes. It would have been ~ 
excellent to have a coloured edition of small size, if there could have been 
an uncoloured one at a more moderate price. But the chief trouble is that the 
publishers insist upon receiving the full subscription (£5) for the work in 
advance, though it must take at least several years to complete it. The work, 
of course, is intrinsically worth all that is asked for it, and more; but the fact 
remains that zoologists are not commonly blessed with superabundant means, 
and are reluctant to part with a five-pound note under the circumstances just 
mentioned. Surely if the conditions of sale were rendered easier the subscrip- 
tions would become so much more numerous that the amount received would be 
considerably greater than at present. T. D. A. CocKERELL. 
