Recently published Ornithological Works, 265 



XXIV. — Notices of recent Ornithological Publications. 



[Continued from p. 154.] 



33. Barrows and Schwarz on the American Crow. 



[The Common Crow of the United States. By Walter B. Barrows 

 and E. A. Schwarz. U. S. Dept. Agricult. Ornith. & Mamm. Bulletin, 

 No. 6, p. 9.] 



Here we have the results of an extended and elaborate 

 investigation into the food of the Common Crow of the 

 U. S, {Corvus americanus) , carried out^ under the superin- 

 tendence of Dr. Merriam, by Messrs. Barrows and Schwarz. 

 It is based on an examination of nearly a thousand stomachs. 

 After summing up the benefits and losses, the verdict is that 

 the " good exceeds the bad, and that this Crow is rather a 

 friend than an enemy to the farmer.^^ 



34. Baur on the Galapagos. 



[The Differentiation of Species on the Galapagos Islands and the Origin 

 of the Group. By G. Baur. Biological Lecture delivered at the Marine 

 Biological Laboratory of Wood's Hole, Summer Session of 1894. Reprint. 

 8vo. Boston, U.S.A. 1895.] 



Mr. Baur's lecture on the Galapagos and the curious 

 phenomena exhibited in the differentiation of species in the 

 various islands is well worthy of perusal. His conclusioD is 

 that only the " subsidence theory " is suflScient to account 

 for the present state of the fauna. 



" At a former period these islands were connected with 

 each other, forming a single large island, which itself, at a 

 still earlier time, was united with the continent, probably 

 with Central America and the West Indies. When this 

 large island was not yet broken up into a series of smaller 

 islands, the number of species must have been very much 

 smaller ; probably there was only one species of Nesomimus, 

 of Certhidea, of Tropidurus, of the Land-Tortoise, and so on. 

 Through isolation into single islands the peculiar differ- 

 entiation of the species began ; an originally single species 

 was differentiated in many different forms ; every, or nearly 

 every, island developed its peculiar races.'' 



