A BIRD-CATCHING SPIDER’S WEB.
This enormous Madagascar spider spins webs so strong that birds are caught and held in them. In one of the large meshes will be seen a small parasitic spider’s web for catching flies and other insects. The smaller spider is not only permitted to do this, but is protected by its host from the attacks of the smaller birds.
Other spiders—as doubtless the Mygale if he can get them—will eat lizards, as the following account by Mr. Frederick Pollock will show: “Having procured from the Deserta Grande some fine specimens of this large and handsome spider (Lycosa—a kind of tarantula) in the early part of this year, and having provided suitable cages with glass lids for them, I was anxious to ascertain how large an animal the largest spider would take; and for this purpose I obtained some lizards about three inches long, including the tail. Three of these lizards were killed and devoured by one spider during the time I kept it. They were eaten bones and head and claws and all, the only remnant of the feast being a small ball about a quarter of an inch in diameter, which was cast aside at the bottom of the cage.”[[138]] But why were not some larger lizards tried, since there was no difficulty about three inches? Every inch would have increased the fun—I mean have added to the scientific interest. But perhaps there were none larger.
Mr. Pollock goes on to say that “the islands of Madeira, Porto Santo, and Deserta Grande all lie within an area about fifty miles across. They have each its own peculiar large Lycosa, no two being alike; and it is a very remarkable fact that these Lycosæ vary in size inversely with the magnitude of the island on which they are found—Madeira, the largest island, having the smallest Lycosa, and Deserta Grande, the smallest island, having by far the largest spider. The mode of defence of all these varieties of Lycosæ is precisely the same. They elevate the thorax, raise the first pair of legs high up, and opening wide asunder their falces, strike at and seize any object, such as the end of a pencil” (or the tail of a lizard) “in a most formidable manner.”[[138]]
There is another lizard-eating spider, or at least a spider that will eat lizards when formally introduced to them, and that in a very scientifically interesting manner, the lizard showing such a lively sense of its situation, and the jaws of the spider working in a way which is very curious. These jaws, it appears, are double, also “cheliform,” “denticulate,” and several other things, from which I gather that there are two pairs, each pair working something like the claws of a crab, but with a sawing action, adapted to their toothed surface. By an extremely beautiful adjustment, when the spider in question seizes its prey, one pair of jaws holds on to it, whilst the other saws into it, and then the pair which has been sawing, holds, and the pair which has been holding, saws, and so on alternately, a division, and yet, at the same time, a combination of labour.
“Like to a double cherry, seeming parted,
But yet an union in partition.”
The efficacy of the arrangement was well tested by an Anglo-Indian scientist upon a lizard three inches long, exclusive this time of the tail. “The spider sprang upon it, and made a seizure immediately behind the shoulder. The poor lizard struggled violently at first, rolling over and over in its agony, but the spider kept firm hold, and gradually sawed away with its double jaws into the very entrails of its victim.”[[139]] There was an interesting variation between this case and the last, where, it will be remembered, the lizards were eaten “bones and head and claws and all,” whereas here “the only parts uneaten were the jaws and part of the skin.” This lizard, however, was “at least five inches long from nose to extremity of tail”; but then, again, the spider must have been larger too, though clearly its meal was something in the nature of a feat, since after it “it remained gorged and motionless for about a fortnight, being much swollen and distended.”[[139]] There is no mention of this in the other case, which would seem to imply that the result was different. If so, we have here a fact of great interest—what fact, scientifically elicited, is not?—but in order to establish it upon a really firm basis, further experiments should be made, and, once more, as the limit of size has evidently not yet been reached, I would recommend a lizard of six inches long.