Address of the Secretary. 15 



preceded them on the Tweeden Birni, the rocky banks of 

 which, clothed with natural wood, were much admired. The 

 lower part of the glen, where it joins the Liddell, presents 

 some good geological sections of the mountain limestone, in 

 which the Bynchonella pleurodon, Productus giganteus, and 

 Terebratula succulus were very abundant ; and Fenestella 

 plebeia, Ceripora rhomhifera, Glauconome pluma, a Poly- 

 pera, and some others covered the surface of the slabs. The 

 water penetrating through the limestone is impregnated with 

 calcareous matter in solution, which is deposited extensively 

 on the twigs, grass, and foliage in the bed of the stream. 

 Large quantities of this deposit are canied off for ornamental 

 gardening, several tons having been carted during this year. 



No new plants were found. Typha latifolia filled some 

 small ponds beside the stream ; polypodium phcegopteris and 

 dryopteris were observed, and many mosses were picked by 

 Mr Jerdan. ^Oenanthe crocata, which was growing at several 

 places, attracted attention, and Noble, one of the guides, 

 stated that it was eaten by the sheep. Goats eat the plant 

 with impunity, and the same animal browses freely on 

 Eorphorhia in eastern countries and in the island of Malta, so 

 much so as to affect the milk, which is poisonous when drunk 

 by human beings, though the plant is innocuous to the goat. 

 Pyrola rotundifolia was found in a glen below the village. 



For the Tynron meeting in August only 4 Members left 

 Dumfries, and on arriving at Thomhill they were met by Dr 

 Grierson, who showed them his very extensive collection of 

 rarities, both dead and living, and as the season was very 

 hot and the grass on the " Doon " burnt up, he succeeded in 

 persuading them not to attempt the ascent, but to visit 

 instead the shady groves of Crichope Glen. It appeared, 

 however, that some few members in the district had actually 

 dared the ascent of Tynroon Doon, and inspected what are 

 supposed to be the remains of an old Fort of some kind on 

 the top of it. 



The last Field Meeting was at Rockhall, &c., on 16tb 

 September. 



