30 Proceedings of the 



neighbourhood, and has the struggle to gain a footing been in a measure 

 successful ? The former idea agrees better with present appearances. 



In the conversation which followed the reading of the paper, Dr. Bossey 

 remarked that each particular kind of cultivation seems to possess its own 

 special kind of weeds. Thus Galium tricome and many other species are 

 associated with the cultivation of corn. He further spoke of the importance 

 to be attached to the introduction of new plants from abroad by their seed 

 getting mixed with foreign seed imported into this country. By this agency 

 many species have been introduced from Germany and other countries. 

 Mr. H. M. Wallis said that he had found dock seed mixed amongst seed 

 from America. He believed that the Dock had originally found its way to 

 America amongst English clover, which is now cultivated there ; so that we 

 are now introducing dock seed produced from seed grown here. Mr. J. 

 Linnell, jun., referring to the locality named in the paper for Ophioglossum 

 Tulgatum, said that it had been found in abundance in a meadow at Eeigate 

 Hill during the past summer. He also mentioned that Orchis ustulata had 

 been met with during the summer on Keigate Hill, a new locality ; and that 

 the snowdrop and tulip had each been found still growing in the localities 

 named in the " Flora of Eeigate." Mr. J. B. Crosfield remarked that although 

 man's operations generally tended towards the extermination of plants, yet 

 in some cases they had the opposite effect. Thus, when the ground is dis- 

 turbed in a place where it has been untouched for a considerable time, it 

 often happens that a crop of plants springs up apparently unconnected with 

 the locality ; and so when a railway is made, many seeds which may have 

 long lain dormant are often brought to the surface by man's agency, and so 

 have the opportunity of germinating. He also referred to the great pro- 

 fusion with which many flowers frequently grow on the sides of a railway 

 embankment or cutting, mentioning several si^ecies that are met with by the 

 line between Eeigate and London. Mr. A. Bennett, in reply to a question 

 as to the occurrence of Teucrium Botrj's near Croydon, mentioned that it 

 was first recorded by Mr. Bower in 1855. It was again met with in more 

 abundance five years ago, growing in some stony fields in a soil somewhat 

 similar to that in which it is found at Box Hill. Mr. Bennett stated in 

 reference to Lepidium Draba, a plant that had been alluded to during the 

 conversation, that it was well authenticated that this species had been 

 introduced and established in this country on the return of the British 

 troops from the Walcheren expedition in 1809. The beds used by the 

 soldiers were tur«ed out near Margate, and were ultimately spread out on 

 the land as a manure, and it was by means of them that the seed got 

 diffused. 



Evening Meeting, Becemher 12th, 1879. — Dr. Bossey read a paper 

 entitled " Thames Mud in relation to Sanitary Science," as follows : — 



The mud of the Thames consists of such substances as are first floated 

 into the river, and then deposited from it — of such organisms, animal and 

 vegetable, as are developed in and upon the matters so deposited, and of 

 such chemical substances as result from decompositions and recombinations 



