( xxxiv ) 



dyeing, &c. Indeed M. Villon's object seems to be to turn 

 this animal tannin to practical account. The great part of 

 the discovery is that it shows tannin to be common both to 

 the animal and vegetable kingdoms, and thus breaks down 

 one of the few remaining boundary-lines between these two 

 main divisions of the organic world. The question still 

 remains whether the tannin found in insects is elaborated by 

 them de novo from their food, or is merely absorbed and 

 assimilated without decomposition, just as we see it is the 

 case with chlorophyll, and, I believe, with alizarine in the 

 genus Timarcha. M. Villon seems to speak in favour of the 

 former opinion, whilst my observations, so far as they have 

 gone, would suggest the latter. Still it is perfectly possible 

 that tannin might be generated in the organs of a Lamellicorn 

 beetle, but not in those of a Carab. It has occurred to me 

 that black patterns on buff or brown grounds may possibly be 

 produced by iron held in solution in the blood of the insect 

 being deposited in some parts of the chitinous tissue rather 

 than in others. On prolonged steeping certain elytra in 

 solutions of iron I have found black lines and spots making 

 their appearance. The power of chitine to take up colouring- 

 matters is considerable ; the specimens given are dyed 

 respectively with magenta, orchil extract, basic aniline blue, 

 and soluble indigo. Chitine when pure does not, however, 

 turn brown or black when steeped in the solutions of iron, 

 thus showing that the presence of tannin is needed for the 

 production of those colours." 



A discussion ensued, in which Prof. Meldola, Mr. Poulton, 

 Dr. Sharp, and others took part. 



August 3, 1887. 

 Dr. David Sharp, M.B., F.Z.S., President, in the chair. 



Donations to the Library were announced, and thanks voted 



to the respective donors. 



Election of Fellows. 

 Mr. John Witherington Peers, M.A.., of Wendover, near 

 Tring; and Mr. it. Gr. Lynam, of the North Staffordshire 



