426 



December 19, 1860. 



Dr. C. T. Jackson, Vice-President, in the Chair. 



Dr. Brewer exhibited two nests of the humming-bird 

 — one from Massachusetts, the other from Georgia. 



It has long been a matter of doubt as to what is the material of 

 which the nest is made. It is soft, white, cottony, homogeneous, 

 and shingled on the outside with lichens ; though evidently of 

 vegetable origin, the precise material was not known. In the 

 Massachusetts nest, it proves to be the down which protects the 

 buds of the oak tree in spring, and in this instance of the red oak ; 

 in the Georgia nest it was of a coarser character, but probably 

 obtained from a similar Southern oak. 



He also exhibited two nests of the summer yellow-bird, one 

 from the island of Grand Manan, the other from Lynn, Mass. 

 The former was made almost entirely of the wool of sheep, many 

 of which are kept on the island ; the fabric is strengthened by a 

 few straws. In this State the nest is usually made of soft flaxen 

 fibres of decayed plants, and of cotton and threads ; the nest ex- 

 hibited was composed of the unusual material of the down of the 

 brake. 



Mr. C. H. Hitchcock made a communication on the 

 geology of Vermont, chiefly in connection with the Ta- 

 conic system. 



The rocks above and below this system are essentially the same 

 in Eastern Vermont and in New York ; the first five or six in the 

 series are exactly the same, commencing with the Laurentian de- 

 posits, and others above are a little different ; the rock containing 

 the trilobite^ of the Primordial fauna is the first which does not 

 conform paleontologically to the New York arrangement ; from 

 the Lower Silurian to the Hudson River group all are found in 

 Vermont, as also their junction one with the other ; over the Hud- 

 son River slates at St. Albans, on Lake Champlain, lies the equiva- 

 lent of the Oneida conglomerate, and over this the trilobitic rock. 

 Emmons considers that there is a fault between this and the rocks 

 to the east, in which Mr. Hitchcock differs from him, finding no 



