Royal Physical Society. 247 



during the formation of such deep and extensive beds. I must, however, 

 content myself with a few words about the organic silex. It is well 

 known that silex forms part of the substance of plants, and that it is in- 

 terwoven in their tissues. Some plants contain more of it than others. 

 This organic silex has caused much speculation as to how such an appa- 

 rently indestructible substance could be decomposed and converted into 

 proper matter for this supply. Am I wrong in supposing that these de- 

 licate and impalpable shields may be sufficiently minute to be drawn up 

 by the sap from the marl used as manure, and by one of those delightful — 

 but at present unknown — processes going on in nature's laboratory, trans- 

 formed into a shape adapted to the want of the growing plant ? However 

 delightful it might be to follow this thought farther, I must desist, and 

 merely suggest that the marl from these deposits, containing so much silex , 

 might probably be used in the same manner as tripoli, first separating 

 the diatomaceae from the lime, which latter, from its peculiar character, 

 might also be used for other economic purposes as well as for manure. 

 Should this be attempted, it could be obtained in almost any quantity. 



V. (1.) Notice of the Horn of a Reindeer (Cervus tarandus, Linn.), found 

 in Dumbartonshire. By John Alexander Smith, M.D. 



At the close of last session, I exhibited to the Society several shells 

 and a deer's horn, which had been recently found during the excava- 

 tion of a cutting on the Forth and Clyde Junction Railway. My 

 friend, James Macfarlane of Balwill, Esq., knowing the district well, 

 was kind enough to draw up at my request a " memorandum," formerly 

 read to the Society ; and I have since been furnished with some additional 

 information. The locality in which the horn, shells, and fragments now on 

 the table were found is situated in the county of Dumbarton, and parish of 

 Kilmaronock, immediately adjoining the hamlet of Croftamie, in the basin 

 of the river Endrick (which flows into Loch Lomond), and at a distance of 

 nearly a mile from that river, and about four miles from the nearest part 

 of Loch Lomond. The superincumbent mass consisted first of the vege- 

 table mould, then of a stiff till about twelve feet thick, containing a large 

 quantity of stones, some of a round form, apparently water- worn, others 

 angular, and many of them of a great size. Under the till was a bed of 

 blue clay about seven feet thick, and at the lower part of this bed, and 

 close upon the sandstone rock, the horn was dug out of the clay at the 

 depth of about eighteen feet ; and at a few yards' distance the shells were 

 found in a similar position, lying at a depth of about twenty-one feet 

 from the surface, the ground cut through rising a little higher at that 

 part. As nearly as can be calculated from the railway plans and sec- 

 tions, these remains lay from 100 to 103 feet above the level of the sea. 

 The shells consisted of the following species : — Gyprina islandica,Astarte 

 ellipiica, and A. compressa, Fusus antiquus, Littorina littorea, and the 



