669 



The author concludes by proposing methods by which the inquiry 

 should in future be conducted, so as to obviate or eliminate this 

 source of error. Such an inquiry, he remarks, would, by exhibit- 

 ing the magnetic and diamagnetic powers under new aspects, lead, 

 in all probability, to important consequences. 



March 18, 1847. 



The MARQUIS OF NORTHAMPTON, President, in the Chair. 



J. R. Christie, Esq. and Thomas Webster, Esq. were elected into 

 the Society. 



" Researches to determine the Number of Species and the Mode 

 of Development of the British Triton." By J. Higginbottom, Esq., 

 F.R.C.S. Communicated by Thomas Bell, Esq., F.R.S. 



The observations of the author, of which he gives a detailed ac- 

 count in the present memoir, have led him to the following con- 

 clusions : — 



Two species only of the genus Triton are met with in England ; 

 namely, the Triton verrucosus and the Lisso-triton punctatus. It is 

 three years before the animal is capable of propagating its species, 

 and four years before it attains its full growth. In its tadpole state, 

 it remains in the water till its legs acquire sufficient strength to 

 quahfy it for progressive motion on land. While a land animal, it 

 is in an active state during the summer, and passes the winter in a 

 state of hybernation ; but does not then, as has been erroneously 

 supposed, remain at the bottom of pools. Very dry, or very wet 

 situations are incompatible with the preservation of life during the 

 period of hybernation. At the expiration of the third year, the 

 triton revisits the water, in the spring season, for the purposes of 

 reproduction, and again leaves it at the commencement of autumn. 

 Impregnation is accomplished through the medium of water, and 

 not by actual contact. The growth and development of the triton 

 are materially influenced by temperature, and but little by the action 

 of light. The triton possesses the power of reproducing its lost 

 limbs, provided the temperature be within the limits of 58° and 75° 

 Fahrenheit ; but at lower temperatures, and during the winter, it 

 has no such power. 



April 15, 1847. 



The MARQUIS OF NORTHAMPTON, President, in the Chair. 



William Baly, M.D., Thomas Flower Ellis, Esq., John Gorham 

 Maitland, Esq., and W. H. C. Plowden, Esq. were elected into the 

 Society. 



