78 Trans. Acad. Sci. of St. Louis 
ealled this a ‘‘paving.’’ The first instance of this sort of thing 
seems to have been cited by Silloway in ‘‘Birds of Fergus 
County, Montana.’’ Peabody (1906), refers to this account but 
I have not had access to it. Silloway described these pavements 
as ‘‘dirt or clods or fragments of cow-chips.’? The pavements 
noted by Peabody were of ‘‘gumbo,’’ of which ‘‘2 or 3 bits’’ 
were used at one nest and 40 at another. A third had ‘‘cow- 
chips.’’ Silloway and Peabody’s accounts (in Montana and 
Wyoming) referred to O. a. leucolaema. Mouseley (1916) was 
the first to record a ‘‘pavement” for praticola. He describes 
it as of cow-chips and (another nest) of flat pebbles or stones. 
In most of the photographs of nests accompanying this article 
a ‘‘paving’’ is visible and in others it is present but the sep- 
arate items have been obliterated by rain. In my opinion prac- 
tically all nests of praticola have this pavement though it may 
vary considerably in shape, size and number of items. See Tables 
5 and 6 for an account of the details of this interesting struc- 
ture at all of the nests at Evanston and Ithaca. 
Mouseley (1916) suggests that the Lark uses for ‘‘paving”’ 
that which is best suited, thus: ‘‘As regards the paving it [the 
bird] seems to have displayed that marvelous instinet which 
birds seem at times to be endowed with, for instead of using 
cow-chips as a paving which, in such a wet, spongy place would 
have been of little good, it resorted to the use of very thin and 
flat stones.’’ In my opinion the bird uses what is most acces- 
sible—at Evanston clods, at Ithaca pebbles—and shows no pre- 
Science whatsoever in the matter. If it does why should it have 
used clods almost exclusively at Evanston which the first rain 
would beat down and wash together when, by going a trifle fur- 
ther, it could have had an admirable assortment of pebbles left by 
the sidewalk contractors? Probably clods, formed by the drying 
of the surface that follows rains on the barren areas that the Lark 
inhabits, constitute the chief materials for ‘‘pavements’’ of 
praticola. That they have not been recorded more frequently 1s 
easily explained: a single rain obliterates a clod pavement and, 
moreover unless attention be called to it, even a freshly lai 
pavement may be overlooked. Thus a photograph of @ nest 
taken by Allen (1925) at Ithaca, shows a good pavement but he 
had not noticed it until the writer called his attention thereunto. 
And again a meager pavement appears in a photograph by Wm. 
