MUSEUM OF COMPARATIVE ZOOLOGY. 165 



boundary between the Floridian and Louisianian fauna? and florae, it 

 would hence seem, may be properly regarded as passing near this 

 point, the portion of the State to the southward being alone properly 

 Floridian, the northern resembling more the Louisianian type.* 



As already observed, Florida, from its excessively marshy charac- 

 ter, is pre-eminently suited to the wants of the grallatorial birds. Im- 

 mense numbers of the heron tribe hence make it their permanent 

 home, while it is the favorite winter resort of numerous species of Gral- 

 he that pass the breeding season far to the northward. Ibises and 

 egretts abound in its swamps and savannas, forming at all times, by 

 their numbers and showy plumage, a characteristic feature of the fauna. 

 In winter the abundance of snipe and other species of Grallce and 

 ducks render it at that season a sportsman's paradise. Florida hence 

 attracts great numbers of sportsmen in winter, through whose reckless 

 and often wanton waste of life the water-fowl, especially of late years, 

 are annually decimated. 



The summer bird fauna of Florida is probably not better represented 

 in species than that of the temperate parts of the continent generally ; 

 but this State being the winter resort of numerous species of spar- 

 rows and warblers, and of those smaller land birds generally that pass 

 the summer in much higher latitudes, its winter bird fauna, as compared 

 with that of the Northern States, is extremely rich. In New England 

 the number of species of birds that can be regarded as " common " in 

 winter does not exceed fifteen,! but in Florida at that season at least 

 five times that number can be so regarded. This, however, accords 

 with a general law of distribution in respect to the relative number of 

 species found at different points in latitude from the arctic zone south- 

 ward, the number increasing in proportion to the decrease of the lati- 

 tude, or with the increa-e of the mean temperature. In winter, through 

 the southward migration of many species, the minimum number of 

 species which in summer is characteristic of the arctic zone is carried 

 down nearly to the Northern States, there being a marked decrease 

 from summer to winter as far south as the warm temperate or sub- 

 tropic belt ; within the tropics, on the contrary, the number of species 

 is far greater in winter than in summer, through the temporary influx 

 of species from colder regions. 



* For a further definition of the Floridian bird fauna, as distinguished from the Louis- 

 ianian, see beyond, Part V. 

 t See American Naturalist, Vol. I, p. 47, March, 1867. 



