70 NATURAL HISTORY OF SELBORNE. 
I describe thus: “It is a size less than the grasshopper-lark; the 
head, back, and coverts of the wings, of a dusky brown, without 
those dark spots of the grasshopper-lark ; over each eye is a milk- 
white stroke; the chin and throat are white, and the under parts 
of a yellowish white ; the rump is tawny, and the feathers of the 
tail sharp-pointed ; the bill is dusky and sharp, and the legs are 
dusky ; the hinder claw long and crooked.” The person that shot 
it says that it sung so like a reed-sparrow that he took it for one; 
and that it sings all night: but this account merits farther inquiry. 
For my part, I suspect it is a second sort of /ocustela, hinted at by 
Dr. Derham in Ray’s Letters: see p. 108.* He also procured me 
a grasshopper-lark. 
The question that you put with regard to those genera of animals 
that are peculiar to America, viz., how they came there, and whence? 
is too puzzling for me to answer; and yet so obvious as often to 
have struck me with wonder. If one looks into the writers on that 
subject little satisfaction is to befound. Ingenious men will readily 
advance plausible arguments to support whatever theory they shall 
choose to maintain ; but then the misfortune is, every one’s hypo- 
thesis is each as good as another’s, since they are all founded on 
conjecture. The late writers of this sort, in whom may be seen 
all the arguments of those that have gone before, as I remember, 
stock America from the western coast of Africa and the south of 
Europe; and then break down the Isthmus that bridged over the 
Atlantic. But this is making use of a violent piece of machinery ; 
it is a difficulty worthy of the interposition of a god! “ Jucredulus 
por 
* Dr. Derham writes—‘“‘ Doubtless this bird was the Zocuste@a in Willoughby’s ornitho- 
logy, and not the vegzlus non-cristatus, which I call the yellow wren, and of which I 
have discovered three distinct species, but not one of them that sings as here described, 
and as I have seen two sorts (if I mistake not) of docustede birds do.”—W. D.—Corves. 
of Ray, Ray Society, p. 96. ; , . 
The bird here meant is ‘‘ the titlark that sings like a grasshopper.” —WILLOUGHBY, p. 
207 ; and the Sadicaria locustella (Selby) alluded to Letter XVI. 
+ The zoology of the New World is essentially distinct from that of the Old, so is that 
of Africa from India, and both the latter from those of Australia and the Pacific. There 
may be a few forms common to some of these divisions, but the great type of the zoology 
of each is distinct. That of the western coast of Africa is quite distinct from that of 
America; among the birds, for instance, which possess the greatest amount of locomotive 
power, none of the migratory species travel from continent to continent, and the generic 
forms even are almost entirely different. In later times, where there is a much more 
frequent communication between Europe and the west coast of Africa, and by means of 
the slave trade between that country and South America and the West Indian islands, 
there have been various introductions from the one country to the other, and particularly 
of the Vegetable Kingdom, but even with these the great mass of both Fauna and Flora 
continue distinct. ‘There is no more interesting study than that of the geographical 
distribution of animals and plants, and of the very remarkable incidents which sometimes 
eccur to effect the transportation of some which are almost entirely without the power of 
crossing seas or oceans. 
