194 SIXTH HEPORT — 1836. 



{zizania) and other grass-seeds, but remained unnoticed in the 

 marshes, until the labours of the husbandman providing them a 

 more abundant repast, they made their appearance in the vici- 

 nity of the fur-posts. Mr. King, in his narrative of Captain 

 Back's expedition, mentions that a flock of scolecopharfiis ferru- 

 gineus continued feeding on the offal of a fishery on Great Slave 

 Lake, lat. 60^°, until late in December. 



Insessores, Scansores. — The jncidce, or typical family of the 

 scansores, are, as we have already mentioned, mostly residen- 

 tiary, yet some of the species are distributed over forty de- 

 grees of latitude. In such cases, many individuals of a species 

 may seek a more southern residence in winter, though the fact 

 cannot be ascertained by consulting ornithological works, in 

 which the migration of a bird is seldom noticed, unless it 

 takes place in large flocks or entirely deserts the district ; but 

 it is undoubtedly true that near the northern limits of a resident 

 species, the individuals are more numerous in summer than in 

 winter. None of the North American picidce have been de- 

 tected in South America. The aiculidcB do not go to the north- 

 ward of the valley of the St. Lawrence, only one species at- 

 taining that parallel ; the majority of them certainly, perhaps 

 the whole, are common to South America also. The certhiadce 

 abound in Mexico, and none of them go far north. The troglo- 

 dytes furviis, or aedon, which has the highest range, extends 

 also furthest to the south, the species, according to the Prince 

 of Musignano, being precisely the same in Surinam. 



Insessores, Tenuirostres. — Of the trochilidce, the only family 

 of the tenuirostral tribe which detaches species northwards from 

 Mexico, the cynanthus colubris breeds as high as the 57th pa- 

 rallel, on the eastern declivity of the Rocky mountains. The 

 trochilus anna, according to Lesson, goes equally high on the 

 coastof the Pacific, and Eschscholtz informs us that the trochilus 

 rufus reaches the 61st degree of latitude on the same shore. 

 The lampornis mango, a Brazilian species, has been detected 

 recently on the peninsula of Florida in the 25th parallel, and the 

 Reverend Mr. Bachman supposes that it is attracted thither 

 by certain tubular flowers, lately introduced into the gardens 

 in that quarter. This beautiful family of birds is numerous 

 in Mexico, the physical conditions of that country ensu- 

 ring them a constant succession of tubular flowers by short mi- 

 grations from the low tierras calientes, Avhich enjoy a tropical 

 heat in winter, to the elevated plains and mountains as spring 

 advances. Lichtenstein informs us that many of the Mexican 

 humming birds pass the summer near the snow line, thus ob- 

 taining by a comparatively short flight a change of climate, which 



1 



