134 Hoy at Society : — 



These results clearly show that, at the temperatures of 100°, 212°, 

 and 300° F., life and its germs had not been destroyed, whilst at 400° 

 F. they had ; for the results of the examination were in this case 

 exactly identical with those of the albumen solution itself; and the 

 life found was doubtless introduced in the preparation of the solution, 

 and was not due to any life having remained in the fluids that had 

 been heated. 



Although perfectly aware of the interesting researches of Professor 

 Melsens, proving that the most intense cold does not destroy the ac- 

 tive power of vaccine lymph, still I thought it desirable to ascertain 

 the effect of a temperature of 15° F. on well-developed germ-life, 

 similar to that which had been subjected to the action of heat. 



Some putrid-meat liquor, therefore, containing a large quantity of 

 microzyma and vibrios, was subjected for twenty hours to the in- 

 fluence of a temperature ranging between the freezing-point of water 

 aad 1 7° below that point, when the ice was melted and the liquor ex- 

 amined. The animalcules retained their vitality, but appeared very 

 languid, and their power of locomotion was greatly decreased. 



Two hours after melting the ice the liquor was again examined, 

 when the animalcules appeared to be as energetic as before. 



June 15, 1871. — General Sir Edward Sabine, K.C.B., President, 

 in the Chair. 



On the Organization of the Fossil Plants of the Coal-measures. — 

 Part II. Ijcpidodendra and Sigillarice. By W. C. Williamson, 

 F.R.S., Professor of Natural History in Owens College, Manchester. 



The Lepidodendron selaginoides described by Mr. Binney, and still 

 more recently by Mr. Carruthers, is taken as the standard of com- 

 parison for numerous other forms. It consists of a central medullary 

 axis composed of a combination of transversely barred vessels with 

 similarly barred cells ; the vessels are arranged without any special 

 linear order. This tissue is closely surrounded by a second and 

 narrower ring, also of barred vessels, but of smaller size, and arranged 

 in vertical laminae which radiate from within outwards. These 

 laminae are separated by short vertical piles of cells, believed to be 

 medullary rays. In the transverse section the intersected mouths 

 of the vessels form radiating lines ; and the whole structure is re- 

 garded as an early type of an exogenous cylinder ; it is from this 

 cylinder alone that the vascular bundles going to the leaves are 

 given off. This woody zone is surrounded by a very thick cortical 

 layer, which is parenchymatous at its inner part, the cells being with- 

 out definite order ; but externally they become prosenchymatous, and 

 are arranged in radiating lines, which latter tendency is observed to 

 manifest itself whenever the bark-cells assume the prosenchymatous 

 type. Outside the bark is an epidermal layer, separated from the 

 rest of the bark by a thin bast-layer of prosenchyma, the cells of 

 which are developed into a tubular and almost vascular form ; but 

 the vessels are never barred, being essentially of the fibrous type. 



