412 Prof. J. B. Steere on the Distribution of 



species of birds collected by the party in these islands, on our 

 return to the United States, the facts above noticed were found 

 to be of wider application and of more importance than was 

 at first supposed, and to point to a law of distribution which, 

 if established, must have great influence upon theories of the 

 evolution of species. 



In this study only the collections made by the members of 

 the party have been used. Great care was taken with these 

 in noting the exact place of collection, sex, colour of eyes, 

 and other particulars, while in the case of many collections 

 formerly made in the islands it was supposed to be sufficient 

 to label them as from the Pbilippines. 



About five thousand specimens of birds were collected by 

 the party, these belonging to about four hundred species. 

 They were collected on seventeen distinct islands of tb.e 

 archipelago, which were chosen, from their size and location, 

 as representative of the whole. 



These collections, whde not comprising examples of all the 

 species known from the islands, are so nearly complete that 

 any just conclusions drawn from their study must be accepted 

 as truths which further exploration will only strengthen. 



The general arrangement followed has been that of Lord 

 Walden and of Dr. Bowdler Sharpe, in their published lists of 

 Philippine birds. The names of genera and species have been 

 made to agree generally witli those given in the ' Catalogue 

 of the Birds in the British Museum/ so far as the volumes of 

 that work had been issued when this paper was first prepared. 



The land-birds of the Philippines collected by the expe- 

 dition, so far as identified, belong to 157 genera and number 

 328 species. 



Of these, six genera (List A) — 



Laniiis, Locustella, 



Motacilla, Acrocephalus, 



Antlius, Phylloscopus, 



— with twelve species, are migratory, with some or all of their 

 species found outside the Philippines, and have been left out 

 of consideration, though the non-migratory species of these 

 genera seem to be distributed according to the same laws that 

 ffovern the other resident birds. 



