550 



Prof. W. C. Williamson. On the [June 17, 



owing to the available energy being greater in the former than in the 

 latter case. 



In conclusion, we would commend this aluminium-iodine reaction 

 to the consideration of other chemists, who may be investigating 

 organic compounds containing oxygen. 



V. Preliminary Note on the Ossification of the Terminal Pha- 

 langes of the Digits." By E. A. Schafer, F.R.S., and F. 

 A. Dixey, B.A. Received Jnne 3, 1880. 



The diaphyses of the ungual phalanges of the digits offer an excep- 

 tion to the usual mode of ossification of diaphysial bones (including 

 the other phalanges) in the fact that the calcification of the cartilage 

 and its attendant changes begins at the tip and not in the centre 

 of the diaphysis. The subperiosteal intramembranous ossification also 

 commences at the same point — the tip, namely, of the cartilage — as a 

 cap-like expansion over the end of the cartilage. The irruption of the 

 osteoblastic subperiosteal tissue also first occurs here, so that this part 

 seems to correspond morphologically with the centre of the shaft of 

 other long bones. The expanded portion of the phalanx which bears 

 the nail, claw, or hoof, is entirely formed by an outgrowth of the sub- 

 periosteal bone, and is not preceded by cartilage. 



A detailed account of the mode of ossification of these phalanges 

 will be shortly published. 



VI. " On the Organisation of the Fossil Plants of the Coal- 

 measnres. Part XL" By W. C. Williamson, F.R.S., Pro- 

 fessor of Botany in the Owens College, Manchester. Re- 

 ceived June 3, 1880. 



(Abstract.) 



M. Renault has recently published a memoir, in which he repro- 

 duces the views of M. Brongniart respecting the relations which the 

 Lepidodendra bear to the Sigillarise, still insisting that the former are 

 cryptogamic Lycopods, whilst the latter are exogenous Gymnosperms. 

 In endeavouring to establish this position, the French paheo-botanist 

 concludes that if the exogenous Diploxyloid stems (i.e., Sigillarian 

 ones) are but matured states of some Lepidodendra, every Sigillarian 

 type of organisation ought to be found in a young or Lepidodendroid 

 form, because, he contends, the type of the central organisation, once 

 established, undergoes no further change with advancing age. In 

 support of his position, he affirms that there are three such Sigillarian 



