Nov. 1, 1899,] 
THE TROPICAL AGRICULTURIST. 
349 
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 sviccessf ul, and it was eminently so in 
the case of Mr. Green. He not only prepared des- 
criptions, 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 Goccidae had to be 
made before the apparently new forms could be re- 
ported 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 sj'nonymy ; 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 beauti- 
ful. There is an introductory portion on the general 
principles of coccidology, including a new classifi- 
cation of the sub-families and full directions for 
collecting and preserving material. There is also 
a chapter on the insecticides 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 else- 
where and presumably introduced into the island. 
The truly native species, almost without exception, 
have proved to possess no economic imporiance ; 
though of course these very species, carried sovie- 
where 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 Aspidiotus 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 
Chionaspis are by no means truly congeneric ; for 
instance the first six, aspirfis^j-at', theae, albizeiae, 
mussaendae, rhododendri, and scrobicularuni, 
belong properly to IIemichionasj)is. 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 wIid do 
not expect to study Coccidae ; while for the coccido- 
logist it is of course essential. Under these cir- 
cumstances 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 pur- 
poses. It would have been excellent to have a 
coloured edition of small size, if there could have 
been an uucoloured 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 sub- 
scriptions would become so much more numerous 
that the amount received would be considerably 
greater than at present. T. D. A. Cockerell. 
(Entomologist's Monthly Alagazine, October.) 
The CocciDiE of Ceylon : by E. Ernest Green. 
P.E.S. Part i, pp. i— xii and 1—103, with 33 plates 
41896); Part ii, pp. xiii— xli and 104—109, with 30 
plates (1896). London : Dulau and Co. 
It is now somewhat over thirty years since 
Signoret commenced liis " Essai suj les Cwlaeu- 
illes," in which de demonstrated by pen and pencil 
that these to many easy very unattractive insects, 
the females of most of which live under a sort 
©f fixed carapace (the "scale") for most of their 
lives, possessed, when examined microscopically, 
beautiful structure, and that the outline of tlie 
pygidium, with its curious denticulations (to- 
gether with the spinnerets, &c.), furnished valuable 
generic and specific characters. For many years 
bignoret found few disciples, and died before 
the full effects of his work manifested themselves. 
We think we may fairly claim that to our vener- 
able colleague Mr. Douglas (now in his 85th year) 
by his papers in this Magazine, was due the 
initial movement that has since spread over the 
whole world by leaps and bounds, and has in 
several instances (such as Icerya Purchasi and 
As23idioti(S x>erniciosus) occasioned government 
solicitude, and the establishment of paid official 
entomologists, whose duty largely it is to look 
after these apparently insignificant scale-bugs. 
There are at the present time many workers 
in this field, and their publications are distributed 
over nearly every medium, and must numljer 
thousands of pages annually, whereas about 
thirty years ago there was nothing. Prominent 
amongst the workers at the present day is Mr. 
Ernest} Gi-een, the author of the book now under 
notice. Members of Mr. Green's family have long 
been associated with Ceylon, and have also beeii 
known as entomologists : they saw the ruin of 
the coffee-trade in the island (by a fungus), and 
the substitution of tea-planting ; it was hwt 
natural that our author, as an entomologist, and 
with a knowledge of the disastrous results of the 
ravages of Coccidce in other parts of the world, 
should have watched with much care their effects 
on the tea-plants, and in so doing his attention 
has been directed to the group as a whole. Mr. 
Green, at the solicitation of the] Planters' Associa- 
tion, while retaining his interest in his former 
occupation, consented to devote himself entirely 
to watching the insect enemies of the planter, 
and to devising and testing remedies. In addi- 
tion to his acquirements as an entomologist, Mr. 
Green possesses the art of delineating (mostly from 
microscopical specimens) insects and dissections of 
insects in an exquisitely delicate manner, and 
one need only glance over the numerous plates 
in the book before us to see that the work is 
that of a master hand, incapable, we might 
venture to say, of being surpassed, and the figures 
have been faithfully reproduceil by chromo-litho- 
graphy (most unfortunately the paper for the 
plates is of a smaller size than the text). The letter- 
press is of the fullest possible nature, with (in 
Part i) a concise summary of the general habits 
and structure of the group. The generic and 
specific details are complete, and the tables of 
genera are made to include those not yet found 
in the island. Mr. Green estimates that about 
200 species inhabit Ceylon, many are apparently 
endemic, others again are cosmopolitan or in- 
troduced. Much interesting detail is given on 
the natural insect enemies of Coccidce, and it was 
news to us that the larvee of one of the Lyccenidas 
(Spalgis E'^jifts, Westw.) feed entirely on "mealy 
bug." 
To Part ii is appended a long chapter on re. 
medial measures and insecticides. It is acknow- 
ledged that this is largely drawn from American 
sources, and the author hopes that amongst the 
remedies some may be found suitable for appli- 
cation in Ceylon should occasion require. Much 
stress is laid upon the necessity for quarantine, 
and in this connection it is stated that all the 
species that have proved noxious in the island 
have either been certainly imported or are of 
general distribution. No undoubtedly endemic 
species has caused any anxiety. Did space permit 
we would touch upon some curiosities of Coccid 
life in the work before us. Without doubt it 
is the most important work that has yet appeared 
on the subject; it is not often one finds scientific 
attaiiiUieuts and icouographic skill PJ£ tiie bigieii 
