1807 ] 71 
at present. I will not here attempt any speculations as to the reason of its 
occurrence, but, if I find my suspicions strengthened by observation, may perhaps 
say something of it at a future time. I may state I consider sexual differences for 
which no object is probable (as those of the orange-tip butterfly) to be really, as 
regards their manner of origin, varieties, as also the difierences constantly occurring 
in conformity with the season of the year, as in Selenia illunaria. — D. Sharp, 
Dumfries. 
Notes on Acari. — Tromhidimn lapidivm, Hermann, occurs just now in countless 
numbers on the flint gravel covering the approaches to Elmersend Station, in this 
neighbourhood. 
Acariis phalangii, De Geer. Of this species, so named from its infesting the 
harvest spider {Phalangiiim Opilio), and described and figured by Curtis under the 
name of Leptus phalangii (" Farm Insects," page 200, and pi. G, figs. 50 t, and 51) 
as occurring on an Elater (ruficaiidis) , I found yesterday two specimens on Lagria 
hirta, Linn. Both of them (one full-, the other half-grown) were attached by the 
rostrum to the head of the beetle, just beneath the left antenna. — Albert Mullek, 
Penge, S.B., J((?;/ Sth, 1867. 
ii^neral Information. 
Swiss Entomological Society. — We are requested to state that this Society has 
appointed Messrs. Dulau and Co., of 37, Soho Square, its agents in England, and 
that they are empowered to receive subscrijstions for the Journal (" Mittheilungen 
der Schweizerischen Entomologischen Gesellschaft ") of the Society. 
Texa7i insects. — Dr. Boheman informs us that Herr Gustav Belfrage, many 
years resident in North America, has now settled in Texas, and is prepared to 
supply entomologists with insects from that State. Address — P. 0. Box 106, 
Houston, Texas, U. S. America. 
"Mimicry and other protective resemblances among animals.'^ — The last number 
of the Westminster Quarterly Review (Jjily, 1867) contains, under the above title, 
one of the most important and exhaustive papers that has ever been written on 
this subject which is now attracting so much attention among naturalists, being a 
resume of the observations of the various writers on mimicry. The reviewer, 
whom we believe we recognise in the person of one of the most accomplished and 
philosophic naturalists of the present age, a devoted follower of, and fellow- worker 
with, Mr. Darwin, brings forward a multitude of proofs of the existence among 
organised lieings of certain laws (subtle, it is true, yet patent to any observer) by 
which the weak are enabled to protect themselves from the strong, and by which 
the latter can more readily sustain themselves in the universal strife raging in 
Nature. No one, whether he be a disciple of the Darwinian school or a follower of 
the old system, can fail to derive, from a careful perusal of this paper, an amount 
of information such as is rarely to be found condensed in so small a space. Many 
curious instances of mimicry of animate or inanimate objects must have struck all 
naturalists, even those who attend only to the Hraited field of British Natural 
History ; but the wi'iter truly observes that " the Natural History of the tropics 
has never yet been studied on the spot with a full appreciation of what to observe 
in this matter. The varied ways in which the colouring and form of animals serve 
for their protection, their strange disguises as vegetable or mineral substances, 
their wonderful mimicry of other beings, offer an almost unworked and inexhaustible 
