[2] It Deserves Notice, That All The Many Specimens Of This
Shell Found By Me In One Spot, Differ As A Marked Variety,
From Another Set Of Specimens Procured From A Different Spot.
[3] Beatson's St. Helena.
Introductory chapter, p. 4.
[4] Among these few insects, I was surprised to find a small
Aphodius (nov. spec.) and an Oryctes, both extremely numerous
under dung. When the island was discovered it certainly
possessed no quadruped, excepting perhaps a mouse: it becomes,
therefore, a difficult point to ascertain, whether these
stercovorous insects have since been imported by accident, or if
aborigines, on what food they formerly subsisted. On the banks
of the Plata, where, from the vast number of cattle and horses,
the fine plains of turf are richly manured, it is vain to seek
the many kinds of dung-feeding beetles, which occur so
abundantly in Europe. I observed only an Oryctes (the insects of
this genus in Europe generally feed on decayed vegetable matter)
and two species of Phanaeus, common in such situations. On the
opposite side of the Cordillera in Chiloe, another species of
Phanaeus is exceedingly abundant, and it buries the dung of the
cattle in large earthen balls beneath the ground. There is
reason to believe that the genus Phanaeus, before the
introduction of cattle, acted as scavengers to man. In Europe,
beetles, which find support in the matter which has already
contributed towards the life of other and larger animals, are so
numerous that there must be considerably more than one hundred
different species. Considering this, and observing what a
quantity of food of this kind is lost on the plains of La Plata,
I imagined I saw an instance where man had disturbed that chain,
by which so many animals are linked together in their native
country. In Van Diemen's Land, however, I found four species of
Onthophagus, two of Aphodius, and one of a third genus, very
abundantly under the dung of cows; yet these latter animals had
been then introduced only thirty-three years. Previous to that
time the kangaroo and some other small animals were the only
quadrupeds; and their dung is of a very different quality from
that of their successors introduced by man. In England the
greater number of stercovorous beetles are confined in their
appetites; that is, they do not depend indifferently on any
quadruped for the means of subsistence. The change, therefore,
in habits which must have taken place in Van Diemen's Land is
highly remarkable. I am indebted to the Rev. F. W. Hope, who, I
hope, will permit me to call him my master in Entomology, for
giving me the names of the foregoing insects.
[5] Monats. der Konig. Akad. d. Wiss. zu Berlin. Vom
April, 1845.
[6] I have described this Bar in detail, in the Lond. and
Edin. Phil. Mag., vol. xix. (1841), p. 257.
End of The Voyage of the Beagle by Charles Darwin
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