26 



efforts to discover their tick-mimics, owing, in all probabilit}', to the slight 

 attention which the group has received at the hands of entomologists and 

 travellers. Other seeds, almost all with a relatively large carunculus, closely 

 resemble compatriot beetles, belonging especially to the groups Chrysomelida 

 and Cassidida. The " raphal line " of the seed represents the line between the 

 closed elytra, and divides the testa into two elytra-like halves, and the 

 mimicry is completed by the prothorox-like carunculus. It was then shown 

 that, although there can be no doubt of the resemblance between seed and 

 insect, it is very difficult to come to a conclusion as to which is the mimic- 

 ing and which the mimicked organism. For the carunculus, which may 

 structurally represent an aborted ovule, it is impossible to suggest any func- 

 tion other than mimicry-completion ; on the other hand, there seems large 

 warrant for the assumption that the beetle derives benefit from its resemblance 

 to the seed. Under these circumstances it was suggested that a parallel 

 mimicry might obtain here, the insect and the seed originally showing some 

 general likeness sufficient to throw off their scent the more unwary of the 

 enemies of either, and that the mimicry might then become more and more 

 perfect by the ordinary operation of natural selection. In order, however, to 

 establish this view, the necessity of observation in the tropics was insisted on. 

 A vote of thanks to Mr. Moore was then proposed by Dr. Herbert Cooper, 

 and seconded by Mr. C. A. Watkins, and, after a few remarks from the 

 lecturer, the meeting terminated. 



JANUARY 16th, 1884.— OEDINARY MEETING. 



ME. WM. BOULTING, L.R.C.P., 



President, in the Chair. 



The Minutes of the previous meeting were read and confirmed. 



Mr. W. Collett was elected a member of the Club. 



Mr. O. Bevil Granville proposed a vote of thanks to Mrs. Ellis for her 

 kindness in having allowed the Club free use of a room for the Museum and 

 Library since the formation of the Club. The collection hart now outgrown 

 this accommodation ; but without the assistance of Mrs. Ellis the Museum 

 could not have reached its present dimensions. Mr. R. M. Gordon seconded 

 the vote of thanks, which was carried unanimouslv. 



A lecture was delivered bv MR. F. W. RUDLER, F.G.S., on " THE 

 NATURAL HISTORY OF THE DIAMOND." The lecturer gave a short 

 history of the use of precious stones for ornamentation, pointing out that in 

 the earliest times the diamond was not valued so highly as other gems, prob- 

 ablj' in consequence of the difficulty of cutting it, the method being then un- 

 known. Although the diamond is mentioned in the early Scriptures as one of 

 the stones in the breastplate of the high priest, the stone referred to was most 

 likely a species of onjTC, as the diamond could not have then been engraved as 

 those stones are said to have been. In early times the diamond was confounded 

 wth the mineral known as rock crystal, which is pure silica crj'stallised in 

 transparent six-sided prisms. Pliny, in his " Natural History," makes the first 

 reliable record of diamonds in an account of six stones, from which descrip- 

 tion three of them can be recognised as diamonds, the others being rock crystal. 

 The geometrical forms which mineral substances assume under favourable 

 circumstances in passing into a solid state are called crystals, from the Greek 

 word krustallos, ice — as the ancients imagined all crystallised minerals to be 

 petrified ice. The difference between a crystallised and an amorphous 



