THE OVEN-BIED. 77 
ing to the roof. The second species described by Mr. Darwin 
is smaller than the other^ which however it resembles in 
the reddish plumage^ the shrill reiterated cry, and a peculiar 
manner of running by starts : by the Spaniards it is called 
Casarita, or the little house-maker. It constructs its nest 
at the bottom of a narrow cylindrical hole of considerable 
length; this hole is usually formed in a low bank of firm 
sandy soil, close to a road or stream. The casarita, accord- 
ing to Mr. Darwin, sometimes selects other situations. At 
Bahia Blanca, the walls are built of hardened mud, and I 
noticed,''^ says this traveller, ^^that one, which enclosed a 
courtyard where I lodged, was penetrated by round holes in 
a score of places. On asking the owner the cause of this, 
he bitterly complained of the little casarita, several of which 
I afterwards observed at work. It is rather curious that, 
although they were constantly flitting over the low wall, they 
must be quite incapable of gaining an idea of thickness, 
even after the shortest circuitous route, for otherwise they 
would not have made so many vain attempts. I do not 
doubt that each bird, as often as it came to dayhght on 
the opposite side, was greatly surprised at the marvellous 
fact.^^ 
The Purple-winged Creeper {TicJiodroma plimicoptera) is 
