1008 



glass, which he described as being chiefly composed of branching 

 elongated tubes, containing molecular spherules at irregular distances, 

 and accompanied with the appearance of moisture adhering to the 

 tubes. Another form was that of a series of molecular spherules touch- 

 ing each other, and presenting amoniliform appearance, this he attri- 

 buted to the escape of those bodies from the tubes, and suggested the 

 probability that this mode of arrangement might be due to an exten- 

 sion of the principle of polarization. He also produced some objects 

 mounted on glass, under talc, in which the paper covering them had 

 been pasted down, and in which a Conferva of an exactly similar ap- 

 pearance was seen branching over the objects, and greatly obscuring 

 them. Mr, Bowerbank also exhibited au aquatic larva, very com- 

 monly found in the water with which London is supplied, in which 

 the circulation is seen in a very beautiful manner, as well as a pecu- 

 liar contraction of the muscles of the limbs, which, in some instances, 

 appear to be composed of a single fasciculus, and in contracting are 

 simply bent at intervals, without exhibiting an appreciable swelling 

 of the fasciculus of ultimate fibres. 



Mr. J. Quekett made some observations on the cause of the irides- 

 cent surface of glass which has been for some years either exposed to 

 the atmosphere or buried in the earth. This was clearly shown to be 

 the result of a decomposition of the surface of the glass, which is thus 

 split up into a vast number of exceedingly fine and close lines, inter- 

 secting each other in every direction, and thus producing the effect 

 described. 



Some observations were made by Mr. E. Quekett, on the crystals 

 contained in the cells of plants. He stated that in most cases the 

 position of these bodies is accidental or uncertain, but in some in- 

 stances, as in the cells of the covering of the seed of the elm, the crys- 

 tals are regularly disposed in all specimens, and appear to be adherent 

 only to the walls of the cells that touch each other in the horizontal 

 plane. Mr. Q. made further observations on the supposed use of these 

 bodies in the vegetable kingdom, and was of opinion, as Professor 

 Bailey of West Point, New York, had stated, that these bodies con- 

 tributed by the decay of the plant, as well as the vegetable matter, to 

 furnish materials for the support of future plants. The enormous 

 quantity (sometimes 80 per cent, in the dried plant), and their com- 

 position, which is oxalate of lime in most cases, seemed adapted, by 

 the decomposition of the oxalate into carbon and oxygen, to furnish 

 two important elements of vegetable structure. — J. W. 



