1829.] 



C 109 ] 



VARIETIES, SCIENTIFIC AND MISCELLANEOUS. 



British Fos.iils Mr. Taylor has pre- 

 pared a valuable list of the fossils hitherto 

 discovered in the British strata, drawn prin- 

 cipally from the works and authority of 

 Mr. Sowerby, to whose indefatigable exer- 

 tions in extending our acquaintance with 

 the fossils of England, geology is under most 

 essential obligation. The list details the 

 genera in each of its divisions, alphabeti- 



cally, giving for each genus the number oC 

 the species most characteristic or abundant 

 in each formation, with the principal locali- 

 ties where they occur. It is not susceptible 

 of abridgement, but some of the results 

 which can be expressed by numbers have 

 been thrown by the author into tables, of 

 which the following is a summary : — 



Total Number of Species known 1 

 (from Wood's Index Testaceo- V 

 logicus) J 



Total Number of Genera 



Total Number of Species 



Carboniferous Order, of Cony-1 



beare. (Species) J 



Carboniferous Beds to Lias. \ 

 (Species) J 



Ancient Strata, to Lias inclusive. \ 

 Total of Species J 



Inferior Oolite to Chalk inclusive \ 

 (Species) j 



Strata above the Chalk (Species). . 



From the Lias to the more recent ) 

 beds. Total of Species J 



It appears, therefore, that the total 

 number of known existing species being 

 about 3,000, the number of fossil species is 

 about 1,300. And the author states, 

 among other inferences from his tables, that 

 the ancient period is characterised by the 

 complex shells, the middle by bivalves, the 

 upper strata by the simple univalves ; while, 

 as we descend in the series of strata, we 

 recede from the existing forms and propor- 

 tions of numbers ; 134 complex species, out 

 of 237, being found in the ancient beds, 

 and only 147, out of 1028, in the more 

 recent. 



Extirpation of the Spleen The extir- 

 pation of the spleen, performed with the 

 necessary precautions, does not induce the 

 death of the animal. I\I. C. A. Schultze, 

 from whose memoir on the subject, read at 

 the Assembly of the Naturalists and Phy- 

 sicians of Ocnnany which took place last 

 year, we derive the information, performed 

 tliis operation twenty-seven times on dogs, 

 cats, goats, and ral)l)its, and lost only one 

 dog, which died tlic 26tli day, but of whicli 

 tlic vena cava had been cut, near the 



stomach, six weeks before the operation. 

 When once the wound is healed, it does not 

 appear that any function is perceptibly 

 deranged. The stomach digests well; 

 only when the animals eat too much, or too 

 quickly, vomiting supervenes with great 

 facility, which may be well explained by the 

 irritation communicated to the diaphragm 

 and to the peritoneum by the effect of the 

 extirpation. The secretion of the bile con- 

 tinues regularly, but in a smaller quantity. 

 The lymph drawn from the thoracic canal 

 has the same physical properties as those of 

 other animals which have not been thus 

 treated. If the extiriJation be performed 

 upon young animals it does not at all im- 

 pede their growth ; not the least influence 

 appears to be exercised upon the nutritive 

 functions. The generative function alone 

 seems to suffer from the extirjiation of the 

 spleen. Thus dogs or cats, operated upon 

 when young, constantly jiroduce a smaller 

 number tlian those belonging to the same 

 Utter wliich have not been thus operated 

 upon. They bring into tlie world one, or 

 at most, two young ones, though their con- 



