158 LETTER FROM MR. W. H. HUDSON. [Mar. 24, 
species) were well-known inhabitants of New Guinea and the neigh- 
bouring islands, with the single exception of Hrythrura trichroa 
(Kittl.), not hitherto recorded as a Papuan species. 
A third letter* on the ornithology of Buenos Ayres, addressed to 
the Secretary by Mr. W. H. Hudson, C.M.Z.S., was read :— 
«There are four Woodpeckers met with in this country [Buenos 
Ayres]. Two of these (Picus mixtus and Chrysoptilus chlorozostus) 
you have seen in my collections. To both these birds the natives 
have given the vulgar name ‘ Come-palo,’ or ‘ Woodeater.’ Both 
of these species are quite common in the places they frequent, and 
are occasionally seen in the thickets south of the Rio Salado; but 
this is the extreme southern limit of their range, and they prefer 
the Sayus forests bordering on the Rio de la Plata. Chrysoptilus 
chlorozostus is sometimes seen to alight on the ground, apparently 
for the purpose of feeding on worms and ants. Its cries are, when 
the bird is excited, loud, rapid, and shrill; at other times it modu- 
lates them to notes exceedingly soft and sorrowful. 
“The third species (the Carpintero blanco, or White Carpenter+) 
affords another illustration of the influence of the riverine wood in 
introducing new species from the north to this country; for this 
bird, which is a native of the northern states of La Plata, is occa- 
sionally found within a few miles of the city of Buenos Ayres, 
though never, to my knowledge, south of it. Probably the diver- 
gence from the typical mottled colours of the Woodpeckers is greater 
in this species than in any other. I am not acquainted with its 
habits. 
«The fourth species is the ‘Carpintero;’ more widely distributed 
and better known than the other members of the genus to which it 
belongs, and also of great interest in reference to the erroneous 
account of its habits in Mr. Darwin’s work, which makes it worthy 
of particular attention. However close an observer a naturalist may 
be, it is not possible for him to know much of a species from seeing 
perhaps one or two individuals in the course of a rapid ride across 
the pampas. Certainly, if Mr. Darwin had truly known the habits 
of the bird, he would not have attempted to adduce from it an argu- 
ment in favour of his theory of the origin of species. In Chap. VI. 
of his well-known work on this subject the author speaks of the 
altered habits, caused by change of habitat and other extraneous 
circumstances, and infers that it would be an easy matter for natural 
selection to step in and alter an animal’s structure so as to make a 
new species of it, after its habits have been so altered. He then 
proceeds to ask whether ‘there can be a more striking instance 
of adaptation given than that of a Woodpecker for climbing trees 
and for seizing the insects in the chinks of the bark;’ and, in 
reference to this, states that there is a Woodpecker inhabiting the 
plains of La Plata, ‘where not a tree grows,’ and which is conse- 
* For Mr. Hudson’s previous letters see anted, p. 87 et p. 108. 
+ [Leuconerpes dominicanus.—P. L. 8.] 
a 
