SCIENTIFIC SOCIETIES. 277 



upper ones are empty, the darts being situated in the lower and larger lobes. 

 These lobes are pyriform and nearly transparent, the upper ones being often 

 ringed with minute spots of a chocolate-brown colour. The situation of the 

 sac is such as does not occur in any other species of dart-bearing snail, 

 being in some cases quite 5 mm. from the genital orifice. Now the dart of 

 this species is about 1*25 mm. in length, and presuming that the dart-sac, 

 when inverted, together with the dart, measures 4 mm., it will be seen that 

 it is quite impossible for this mollusk to use its weapon. I have dissected 

 them at all times of the year, but have never met with a specimen in which 

 the darts were absent. I have also carefully watched them uniting, but 

 have never witnessed the use of the darts. I am aware that owing to the 

 small size of the organ it is quite possible that it might be overlooked ; but 

 from the numerous experiments I have made, extending as they do over 

 three years, I feel sure I should have seen it, at one time or another, had 

 it been used. It would appear then that this species of Helix, although 

 possessing the darts, is incapable of using them. If this be so, it is, I think, 

 a strong point in favour of the theory I advanced some three years ago 

 as to their use— viz., that they are degenerate weapons of defence, and that 

 in the past they were much stronger and oftener-used organs. It would 

 be interesting to know whether species possessing two darts — viz., H.erice- 

 torum, H. hispida, and H. concinna — ever use both in one encounter. I have 

 never seen both used, but it is very likely that this happens in prolonged 

 encounters. — W. E. Colltnge (Hon. Assistant Curator, Conchological Soc. 

 Gt. Brit., Leeds). 



SCIENTIFIC SOCIETIES, 



Linnean Society of London. 



May 24, 1890, Anniversary Meeting. — Mr. W. Carruthers, F.R.S., 

 President, in the chair. 



Messrs. W. West, J. B. Carruthers, and J. Sidney Turner were 

 admitted Fellows. 



The Treasurer presented his Annual Report, duly audited ; and the 

 Secretary having announced the elections and deaths of Fellows during 

 the past year, the President proceeded to deliver his Annual Address. Tn 

 this he dealt with the distribution of British plants both before and after 

 the Glacial Period (making special allusion to the discoveries of Mr. 

 Clement Reid amongst the vegetation of the Cromer Forest Bed), and 

 showed that the forms which have come down to us at the present 



