408 Royal Institution. 



purpurea : rostro et pedibus nigris : uropygii plumis laxis admodum 

 elongatis. Long. tot. m. 0*175 ; alae m. 0095 ; caudse m. 0"065., 

 Inhabits moist woods in Peru, where it keeps at the tops of tli^ 

 trees. It generally lives in pairs ; its flight is very hght. 



VIII. Studies on the Anodontce of the Aube, by H. Drouet. Se- 

 cond article (V. pp. 244-251, and VI. pp. 285-290). 



In this article the author describes those Anodontce of the Depart- 

 ment of the Aube which belong to the second and third groups of the 

 genus, — the AnatincB and Piscinales, that is to say, the species alUed 

 to A. anatina and piscinalis. Of the first of these groups there are 

 three species — namely, " 



5. A. anatina {Mytilus anatinus, Linn.). 



6. A. Rayii, Dup. 



7. A. parvula, Drouet. {A. coarctata, Potiez and Michaud ; the 

 name changed because previously employed for an American species.) 



The second group also includes three species — namely, 



8. A. piscinalis, Nilss. 



9. A. Milletii, Ray and Drouet. 



10. A. rostrata (Kok.), Rossm. 



yfe defer gi^'ing the characters of these species until the comple- 

 tion of the memoir. 



These numbers also contain reports of the meetings of the Academy 

 of Sciences from the 29th of March to the 2 1 st of June 1 852, and also 

 some notices of new works. 



PROCEEDINGS OF LEARNED SOCIETIES. 



ROYAL INSTITUTION OF GREAT BRITAIN. 



April 15, 1853. 



On the Identity of Structure of Plants and Animals. 

 By Thomas H. Huxley, F.R.S. 



The lecturer commenced by referring to his endeavour last year* to 

 show that the distinction between living creatures, and those which 

 do not live, consists in the fact, that while the latter tend to remain 

 as they are, unless the operation of some internal cause effect a 

 change in their condition, the former have no such inertia, but pass 

 spontaneously through a definite succession of states, — different in 

 kind and order of succession for different species, but always identical 

 in the members of the same species. 



There is, however, another character of living bodies — Organiza- 

 tion, which is usually supposed to be their most striking peculiarity 

 as contrasted with beings which do not live ; and it was to the essen- 

 tial nature of Organization that the lecturer on the present occasion 

 desired to direct attention. 



* " On Animal Individuality," Annals, vol. ix. p. 505. 



1 



