OCR Text |
Show 302 TIERRA DEL FUEGO. June, 1834. damp and cold limit not one occurs. That the climate would not have suited some of the orders, such as lizards, might have been foreseen ; but with respect to frogs, this was not so obvious. Coleopterous insects occur in very small numbers. Until ' I had endeavoured by every means to find them, I could not believe, that a country as large as Scotland, covered with vegetable productions, and with a variety of stations, would ever have been so unproductive. The greater part of my small collection consists of alpine insects (Harpalidce and Heteromera) found beneath stones, above the limit of the forest. Lower down, with the exception of some few Curculiones scarcely any could be found. The Chrysomelidre, which are so pre-eminently characteristic of the Tropics, are here almost entirely absent.* This must depend on the climate; for the quantity of vegetable matter is superfluously great. In the hottest part of the summer the mean of the maxima for thirty-seven successive days was 55°, and the thermometer .on some of the days rose to 60° ; yet there were no orthoptera, very few diptera, lepidoptera, or hymenoptera. In the pools of water I found but few aquatic beetles, and not any fresh-water shells. Succinea at first appears an exception· but here it must be called a terrestrial species, for it lives o~ the damp herbage far from water. Land shells could only be procured in the same situations with the alpine beetles. I have already contrasted the climate, as well as the general appea:ance of ~ierra del Fuego with that of Patagonia; and the difference IS strongly exemplified in the entomology. • I believe I must except one alpine Haltica, and a single specimen of a ~elasoma. !'1~'· Waterhouse, who was good enough to look at my coll~ ctwn fr~m this place, tells me, that of the Harpalidre there are eight or nme spec1es,-the forms of the greater number being very peculiar ; of Heteromera, four or five species ; of Rhyncophora six or seven . and of th~ f~llowing families one species in each : Staphylinidre, Elateridre, Ccbnomdre, Melolonthidre The species in the other orders, were even fewer. In all the orders, the scarcity of the individuals was even more rema1·kable than that of the species. June, 1834. ZOOLOGY. 303 I do not believe they have a species in common; certainly the o-eneral character of the insects is widely different. 0 If we turn from the land to the sea, we shall find the latter as abundantly stocked with living creatures as the former is poorly so. In all parts of the world a rocky and partially protected shore perhaps supports, in a given space, a greater number of individual animals than any other kind of station. Here, under every stone, numerous crawling creatures swarmed, and especially crustacea of the family of Cymotlwades. The number of Sphreroma was truly wonderful: as these animals, when coiled up, have some resemblance to Trilobites, they were an interesting sight to a geologist. On the tidal rocks patelliform shells of large size were very abundant. Even at the depth of forty or fifty fathoms, the bottom of the sea was far from sterile, as was shown by the abundance of small strong corallines. There is one marine production, which from its importance is worthy of a particular history. It is the kelp or Puc us giganteus of Solander. This plant grows on every rock from low-water mark to a great depth, both on the outer coast and within the channels. I believe, during the voyages of the Adventure and Beagle, not one rock near the surface was discovered ' which was not buoyed by this flo.a tin.g weed. The good service it thus affords to vessels nav1gatmg near this stormy land is evident; and it certain~y has saved rna~! a one from being wrecked. I know few th1~gs_ more ~urpnsmg than to see this plant growing and :flounshmg am1dst those great breakers of the western ocean, which no mass. of rock, let it be ever so hard, can long resist. The stem IS round, slimy, and smooth, and seldom has a diameter of so much as an inch. A few taken together are sufficiently strong to support the weight of the large loose stones to which in the inland channels they grow attached; and some of these stones are so heavy, that when drawn to the surface they can scarcely be lifted into a boat by one person. Captain Cook, in his second voyage, says, that at Kerguelen Land " some of this weed is of a most enormous |