368 ANNUAL OF SCIENTIFIC DISCOVERY. 



Indian Ocean, which have been considered the same. Holbrook describes the 

 Tryonix of Georgia as existing in the Northern Lakes, and he traces the exact 

 course by which it could ascend along the coast and up the Mississippi river to 

 the lakes. But Prof. Agassiz finds that there are four different species hi the 

 United States, three of which are to be included in the one species of Hol- 

 brook, and that each species has its own limited locality. 



The Chelidra, or Snapping Turtles, have the most extensive geographical 

 range of any of the chelonians. The snapping turtle of Massachusetts is found 

 in South Carolina, Alabama, Louisiana, Missouri, and even at the head waters 

 of the Osage. 



Of the family of Emydas, E. Blandingii is the true type. The swimming 

 Emydee are either southern or western species ; there are none in New Eng- 

 land except those which have only a limited power of swimming. 



Emys Oregonensis was described by Nuttall as existing west of the Rocky 

 Mountains. Prof. Agassiz doubts its existence west of the Rocky Mountains, 

 because no turtles have been found in those high regions lying between the 

 Rocky Mountains and the Sierra Nevada. Upon the Alleghanies turtles have 

 been found at a height of eleven hundred feet only, and there are no indications 

 of their existence above this height. He has had two specimens from localities 

 east of the Rocky Mountains, one of which was brought from Minnesota. He 

 thinks Mr. Nuttall's specimen must have come from this side of the mountains. 



Prof. Agassiz concluded that there is no general law regulating the dis- 

 tribution of the chelonians of North America, They are distributed through 

 four grand divisions of the country, a north-eastern, a southern, and a Pacific 

 range. The facts of their geographical distribution are now well established, 

 but the reasons are by no means evident at present. The probability is, that 

 different individuals of the same species of animals are adapted, by peculiar 

 organizations, to different climacteric influences, and that there is no general 

 law of distribution for which physical agents can account. 



OBSERVATIONS ON DEAFNESS. 



Granville "\Vhite, Esq., communicates to the New York Post the following 

 observations on deafness : 



Many years ago, while pursuing an investigation of a psychological nature, 

 we obtained the discovery that the sound which is produced by inserting the 

 fingers within the ears, or by covering them with the hands, is occasioned by 

 the circulation throughout the body, and is conveyed to the hearing through 

 the hand. Should another individual close our ears with his hands, the rum- 

 bling sound which is obtained proceeds from him. No lifeless body can pro- 

 duce the same, unless it acts as a conductor from the hand or person who 

 supports it. Hence it may be determined, by a reference to the organ of 

 hearing, when the blood ceases to flow and life becomes extinct. 



By inserting a cork within the ear inclining the head for the purpose 

 with no other support than the ear's orifice, a very slight sound only can be 

 obtained, which is caused by its contact with the sides of the orifice, and 

 thence conducted to the tympanum; but, by pinching the cork with the 

 fingers, the buzzing will' be increased to such an extent as to furnish sufficient 



