310 Proceedings of Philosophical Societies. ['Oct. 



tions, we shall hero notice some memoirs which have been pre- 

 sented to the Class, but of which the verification is not yet 

 finished, reserving to ourselves the liberty of returning to them 

 next year, and of making known the opinion which has been 

 formed of them. 



M. de Blainville, Joint Professor to the Faculty of Sciences 

 of Paris, has described at fill} length the forms of articulation of 

 the fore-arm and arm in different animals, and determined the 

 motions which each of these forms makes necessary, chiefly with 

 regard to the greater or smaller facility of rotation. This dis- 

 sertation, on a point of importance relative to the mechanism 

 of animals is interesting also, as far as regards their classifica- 

 tion ; for the degree of rotation of the fore-arm having con- 

 siderable influence on the address of the animals, ought to be 

 considered, as far as regards the degree of perfection, and of 

 course influences their natural affinities. 



The same anatomist has presented a memoir on the form of 

 the sternum in birds. As this bone, or rather this great bony 

 surface, resulting (as M. GeofFroy has shown) from the union 

 of five different bones, gives origin to the principal muscles of 

 the bird, the more solid and extended it is, the more solid a 

 point of support does it furnish to these muscles, and the more 

 ought it to contribute to render the flight powerful. It ought 

 therefore to have an influence over the whole economy of the 

 bird, and give useful indications respecting the classification of 

 these animals. M. de Blainville draws his indications from 

 the membranous spaces, more or less extended, which supply 

 the place of bone in a part of the sternum. He adds the con- 

 sideration of the fork, and of some organs connected with it, 

 and in most cases finds a great agreement between the dispo- 

 sition of these parts and the natural families. However, there 

 exist exceptions so manifest that we cannot entirely confide in 

 this new way of classification. 



M. Marcel de Serres, Professor to the Faculty of Sciences of 

 Montpelier, has drawn up a laborious work on the anatomy of 

 insects, and particularly on their intestinal canal, which he has 

 described with much detail in a great number of species. His 

 object was to determine the functions peculiar to the different 

 parts of the canal and its appendages: and, besides his dissec- 

 tions, he has made ingenious experiments on living individuals. 

 Coloured liquors injected into the cavity of the peritoneum were 

 absorbed by long slender vessels, which always adhere to some 

 part of the intestinal canal : hence he conceives that the use of 

 these vessels is to secrete from the common mass of humors 

 digestive liquors, and to throw them into the canal. An atten- 

 tive examination of certain sacks, which in some genera have 

 been considered as stomachs, in others as ccecums, and the cer- 



