the birds in struggling to get possession of those already occupied by stronger species, only shows that the habit or instinct has not been modified to suit a change in the conditions--_i. e._ a diminishing number of ovens to breed in, with, perhaps, the increase of other stronger species possessing the same habit. But while the instinct thus survives too strongly in the country birds, many individuals have taken to a town life, and acquired the new habit of breeding in holes in brick walls. Probably this race of town birds will eventually colonize the rural districts, and usurp the place of the country birds, which will then be placed at a disadvantage. 90. SYCALIS LUTEA (d'Orb. et Lafr.). (YELLOW SEED-FINCH.) +Sycalis chloropis+, _Burm. La-Plata Reise_, ii. p. 489 (Mendoza and Catamarca), +Sycalis lutea+, _Scl. Ibis_, 1872, p. 46, pl. ii. fig. 2. _Description._--Dark yellow; rump and body below brighter; wings and tail brownish black, edged with yellow; under wing-coverts pale yellow; inner margins of wing-feathers pale brown: whole length 5·5 inches, wing 3·2, tail 2·1. _Female_ similar, but duller and more brownish. _Hab._ Andes of Peru, Bolivia, and Argentina. Prof. Burmeister obtained examples of this species near Mendoza. In my revision of the genus published in 1872, I referred the specimens (upon some of which Prof. Burmeister based his species _S. chloropis_) to _S. uropygialis_. I now find that this was an error, and that they really belong to _S. lutea_.--P. L. S. 91. SYCALIS LUTEOLA (Sparrm.). (MISTO SEED-FINCH.) +Sycalis luteola+, _Scl. Ibis_, 1872, p. 44; _Scl. et Salv. Nomencl._ p. 85; _Durnford, Ibis_, 1877, p. 172 (Buenos Ayres), et 1878, p. 394 (Centr. Pat.); _Barrows, Bull. Nutt. Orn. Cl._ viii. p. 132 (Entrerios). +Sycalis luteiventris+, _Burm. La-Plata Reise_, ii. p. 489. _Description._--Above light olive-green, marked with dusky stripes; wing-feathers blackish, with pale brownish edges; tail-feathers the same; beneath, throat and chest dusky buff, lower breast and belly yellow; bill and feet horn-colour; total length 5·0 inches, wing 2·6, tail 2·0. _Female_ similar, but not so bright. _Hab._ S. America, from Colombia to Chili. This is a slender, graceful bird, less than the Canary in size, the whole upper plumage yellowish olive, with dun markings, the lower surface of a dull yellow. The female is a little smaller than the male, and her colours are somewhat dimmer.