144 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
it is said they remain there during the whole year, and that they breed in the 
marshes. During the day they rest in flocks on the grassy plains, at some 
distance from the water. Being at anchor in a small vessel, in one of the deep 
creeks between the islands in the Parana, as the evening drew to a close, one of 
these scissor-beaks suddenly appeared. The water was quite still, and many 
little fish were rising. The bird continued for a long time to skim the surface ; 
flying in its wild and irregular manner up and down the narrow canal, now dark 
with the growing night and the shadows of the overhanging trees. At Monte 
Video, I observed that large flocks remained during the day on the mud banks, 
at the head of the harbour ; in the same manner as those which I observed on the 
grassy plains near the Parana. Every evening they took flight in a straight line 
seaward. From these facts, I suspect, that the Rhynchops frequently fishes by 
night, at which time, many of the lower animals come more abundantly to the 
surface than during the day. I was led by these facts to speculate on the 
possibility of the bill of the Rhynchops, which is so pliable, being a delicate organ 
of touch. But Mr. Owen, who was kind enough to examine the head of one, 
which I brought home in spirits, writes to me, (August 7, 1837,) that — 
“ The result of the dissection of the head of the Rhynchops, comparatively with 
that of the head of the duck, is not what you anticipated. The facial, or sensitive 
branches of the fifth pair of nerves, are very small ; the third division in particular, 
is filamentary, and I have not been able to trace it beyond the soft integument at 
the angles of the mouth. After removing with care, the thin horny covering of 
the beak, I cannot perceive any trace of those nervous expansions which are so 
remarkable in the lamelli-rostral aquatic birds ; and which in them supply the 
tooth-like process, and soft marginal covering of the mandibles. Nevertheless, 
when we remember how sensitive a hair is, through the nerve situated at its 
base, though without any in its substance, it would not be safe to deny 
altogether, a sensitive faculty in the beak of the Rhynchops.” 
M. Lesson (Manuel d’Ornithologie, vol. ii. p. 385.) has stated, that he has 
seen these birds opening the shells of the Mactrae, buried in the sandbanks on the 
coast of Chile. From their weak bills, with the lower mandible so much 
produced, their short legs and long wings, it seems very improbable that this can 
be a general habit, although it may sometimes be resorted to. Wilson, who was 
well acquainted with this bird, does not believe “ the report of its frequenting 
oyster beds, and feeding on these fish.” The existence, however, of this same 
report in the United States, makes the question, whether the Rhynchops does not 
sometimes turn the peculiar structure of its beak to this purpose, worthy of further 
investigation. 
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