130 MEETING OF THE BRITISH ASSOCIATION 



of the two methods. For instance, the red and coralline crag arc 

 supposed, by Deshayes, to contain the same number of extinct spe- 

 cies, and by the per centage test they, therefore, present an equal 

 approximation to the 7 aces now in existence ; but if the shells which 

 Deshayes thinks he can identify with those now inhabiting the Ger- 

 man ocean are rejected, and the extinct testacea alone compared with 

 living types, the forms most remote from existing species will be 

 found to occur in that series which have been derived from the 

 coralline crag. The author then changed his line of argument, and 

 assuming that there is a general agreement among conchologists as 

 to the characters which should be depended upon in discriminating 

 species, and also that the per centage test is the true method of ob- 

 taining relations of analogy, he proceeded to inquire how far the as- 

 sociation of organic remains in regularly stratified deposits implies 

 their previous contemporaneous existence, and then pointed out the 

 effect of causes now in operation upon the earth's surface, in refer- 

 ence to the erroneous conclusions which will be formed by future 

 geologists, should they follow the same course of induction as that 

 which has been pursued by Mr. Lyell. A long discussion followed, 

 in which Dr. Buckland, the Marquis of Northampton, Professor 

 Sedgwick, Mr. Greenough, and Mr. Murchison, took part. 



Section D. — Zoology and Botany. 



President — Professor Henslow . 



Vice-Presidents — Rev. F. W. Hope, Dr. T. Richardson, Professor Royle. 



Secretaries — John Curtis, Esq., Professor Don, Dr. Riley, S. Rootsey, Esq. 



Committee — C. Babington, Esq., J. E. Bowman, Esq., T. C. Eyton, Esq., 

 Hon. Chas. Harris, Rev. Mr. Jenyns, T. Mack ay, Esq., Rev. M. 

 Phelps, Richard Taylor, Esq., Professor Wilson, William Yarrell, Esq., 

 W. C. Hewitson, Professor Scouler, Dr. Jacob, Rev. Mr. Ellecombe, 

 G. J. Jeffrys, Esq., R. M. Ball, Esq., Col. Sykes, J. L. Knapp, Esq., 

 N. Vigors, Esq., E. Forster, Esq. 



Monday. — Dr. Richardson commenced the proceedings of the sec- 

 tion by reading the introductory portion of his report on North 

 American Zoology, comprising remarks on the plrysical geography 

 and climate of the country. 



A living specimen of the Aranea avicularia, Linn., or Mi/gale 

 avicularia, which is of the spider tribe, was exhibited by Mr. Root- 

 sey, who made some observations on the subject. 



Mr. Rootsey mentioned the result of various experiments he had 

 made in extracting sugar, spirit, &c. from mangel wurzel, or Beta 

 macro rrhiza, and converting the plant into malt, specimens of which 

 were exhibited to the section. The sugar was obtained in strong 

 crystals, and the refuse of the plant was dried on a malt kiln at a 

 proper temperature, where it acquired the flavour and properties of 

 common malt, and afforded an excellent beverage. The molasses 

 weie fermented into a spirit, the flavour of which was comparable 

 to the peach brandy of America. Forty tons of the plant, which 



