191 



these stonv substances, which seemed to be a sort of nucleus 

 around which the woody rings grew ; the little pipe of stone ran 

 along the centre, in some places closely embraced by the wood 

 for several inches, while at others a little reddish powder inter- 

 vened between it and the wood. Whether it is found in all the 

 trees he did not know. The specimens were referred to Dr. 

 Hayes to report upon. 



Dr. White presented, in the name of Mr. John H. Bra- 

 zer, three specimens of Siredon from Canon Lake, four- 

 teen miles north of Great Salt Lake City, the lake being 

 about 8,900 feet above the level of the sea. They are 

 there believed to possess electrical powers, which is prob- 

 ably untrue. The thanks of the Society were voted for 

 the donation. 



Dr. C. T. Jackson read a letter from Dr. Evans, an- 

 nouncing the continuance of the efforts to obtain the 

 Oregon meteorite ; and alluding to the discovery of a 

 large iron mountain in that Territory, and the occurrence 

 of 47 per cent, of platinum in some of the black sand of 

 the Pacific coast. 



Prof. Agassiz gave a sketch of what he considered the 

 best arrangement of a Zoological Museum. 



In the great collections, he said, even that at the British Mu- 

 seum, the sole object seems hitherto to have been to exhibit ani- 

 mals according to their supposed natural affinities ; as systems of 

 classification vary very much, of course no harmony of arrange- 

 ment can be expected on this plan. He thought something bet- 

 ter was now wanted, and he intended to arrange the Cambridge 

 Zoological Museum in a totally different manner, viz : according 

 to natural zoological provinces ; in this way, he hoped to be able to 

 define such provinces, which as yet were but imperfectly known, 

 and to arrive at important conclusions on the correlations of ani- 

 mals of the different classes. He intended to do the same with 

 fossils, showing independent creations and distinct zoological prov- 

 inces in geological as well as modern times. For purposes of 



