296 SOME NEW BOOKS [october 



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, carried so?newhere else, may yet become notorious. 



An unfortunate conservation, as it seems to the present writer, is shown in 

 regard to genera. The species assigned to Asjndiotus represent at least five 

 very distinct groups, which are at least of sub-generic value. Aonidia is made 

 to include very diverse forms, including three distinct generic types. Similarly 

 the twenty-six species assigned to Chio?ias2)is are by no means truly congeneric ; 

 for instance the first six, aspidistrae, theae, albizziae, musmendae, rhododendri, and 

 scrobicidarum, belong properly to Hemirhionaspis. 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. 



