468 



young cells. The excentric cells of this period were all productive, 

 and so, able to form new centres. The number of centres, however, 

 were always limited, owing to the liquefaction and absorption of nu- 

 merous periphei-al cells. 



The author, iu the concluding part of his papei*, stated, that dur- 

 ing his observations, he was led to perceive the existence of many 

 beautiful analogies between the Entozoa and the species belonging 

 to other classes of the animal kingdom. 



The volvox amonor the infusoria, he considered as the analogue of 

 the Hydatid, and illustrated this by examining their economy com- 

 paratively. 



The Alcyonidium among the Polyps, is the analogue of the new 

 form of Acephalocyst. Ova in both cases being developed, 1st, 

 for the purpose of increasing the bulk of the parent group; and, 

 2d, for the purpose of being distributed generally, to form se- 

 parate and independent groups. In the function of nutrition the 

 analogy also held true, inasmuch as each of the stomata or disks, it 

 may be, supplied nourishment to the whole gi'oup, as well as to its 

 own particular part ; in the Alcyonidium, each polype acts as a mouth 

 for the ^^up. 



Proceeding upwards in the scale, the author looks upon Diplozoon 

 as the analogue of the Asterias, Tristoma, as that of Scutella and Dis- 

 toma, that of Echinus ; and brought forward an interesting observa- 

 tion, which he thought decisive as to the propriety of the analogies 

 drawn between these Entozoa and Echinodermata, namely, that as 

 the Echinus is merely an Asterias, with the rays folded back, so as 

 to meet at the tips and form a globe, so is the Distoma merely a 

 Diplozoon, with the two bodies folded together. 



The Acanthocephala, of which the Echinorynchi are the types, 

 are analoo-ues of the Crustacea, through the Lerneaj. The Ccelelmin- 

 tha, of which the Lumbricoides are the types, are analogous to the 

 Annelida through the Lumbrici. 



2. Account of a Repetition of Dr Samuel Brown's Processes for 

 the Conversion of Carbon into Silicon. By George Wilson, 

 M.D., Lecturer on Chemistry ; and John Crombie Brown, 

 Esq. Communicated by the Secretary. 



The authors commenced with an account of the trials they made 

 with the Cyanide of lead ; which, according to Dr Brown's most 

 recent announcement, is resolved by his process into gaseous nitrogen 



