1820.] Physical Science during the Year 1819. Ill 



generally admitted. All the acephala, if we except the old 

 genera Teuedo and Pholas, are furnished at their hinge with 

 an elastic ligament that opens their shells. They have one or 

 two muscles and the same number of elastic ligaments to act 

 against this opening power ; and the force of the elastic abduc- 

 tive ligament is sufficient to act so as nearly to close the shells, 

 the valves being sufficiently opened to admit only of that quan- 

 tity of water necessary to convey food, and to serve the purposes 

 of' respiration. — (See Bull, des Sciences, 1818, p. 14.) The 

 valves can readily be closed completely at the will of the animal 

 by a veiy shght action of their strong abductive muscles. 



Classes of uncertain Situation. 



Class, Entozoa. 



An admirable work on this subject, from the long experience 

 of Rodolphi, was published towards the end of 1819, entitled, 

 " Entozoorum Synopsis," in which all the known intestinal 

 worms are systematically arranged and described ; with various 

 copious indices to facilitate the investigation of the species. 

 De Blainville has given an admirable analysis of this work in the 

 March number of the Journal de Physique. 



III. Physiology. 

 By a Friend. 



In the course of the last year this important branch of know- 

 ledge has received but few additions. Some of these have been 

 already noticed under other heads. A few others remain to be 

 briefly related here. 



I . Sanguification and iheBlood inGeneral. — The observations of 

 Mr. Bauer on this subject, as related by Sir E. Home, are inte- 

 resting, if they can be relied on. Mr.B. thinks he has ascertained 

 that the coagulable lymph or fibrin exists v.hen circulating in the 

 living body in a state of perfect solution in the serum, and that 

 what is termed the spontaneous coagulation of the blood, consists 

 in the separation of this lymph or fibrin in the form of an infinite 

 number of globules of about -^— th of an inch in diameter, 

 which, by adhering together, constitute the solid mass termed 

 Jihrin obtained from coagulated blood, &c. These globules have 

 been termed by Sir E. Home lymph globules, to distinguish them 

 from the red globules. 



Mr. B. attempted to trace the origin of these lymph globules, 

 and also the red globules found in the blood ; and he states that 

 they are first to be seen in the mucus of the pyloric portion of 

 the stomach and of the duodenum. On examining the contents 



