Page:The Zoologist, 4th series, vol 2 (1898).djvu/45

Rh distinct stridulation may be easily produced artificially by rubbing the leg and palp together, the long "notes" on the coxa of the first leg giving rise to a distinct "click, click" when scraped against the spines on the maxilla; while the spines on the trochanter of the first leg, when rubbed against the stiff brush of hairs on the trochanter of the palp, gives out a sound resembling the rustling of a silk dress.

But what is to be said respecting the function of these organs, and what evidence, it may be asked, can be adduced in support of the view that they subserve stridulation? To this question the answer must be that so far as the African species are concerned there is no direct evidence based upon observation of the living animal to show what part they play in the Spider's economy. But that their true and probably sole function is the emission of sound, as has been claimed in the preceding pages, is so strongly supported as to reach practical certainty from what is known of the function of the analogous organ detected by Wood-Mason in the Assamese genus Musagetes.

Mr. Peal, it appears, was the first to notice the phenomenon. His gardener, while engaged in digging up a field, unearthed one of these great Spiders, and, not being a collector, naturally enough proceeded to strike at it with his hoe, with the object of ridding the world of such vermin. Thereupon the Spider raised itself upon its two pairs of hind legs, brandished the two remaining pairs in the air, opened its jaws, and waved its palpi up and down, scraping the basal segment to and fro against the outer surface of the mandible, and emitting a sound subsequently described by Wood-Mason as resembling that produced by rapidly dropping shot on a china plate. Fortunately Mr. Peal rescued this historic Spider from the gardener, and afterwards had the satisfaction of seeing it repeat the performance when attacked by a cat. In confirmation of this story, it may be added that Mr. E.W. Pickard-Cambridge told me recently, in course of conversation, that one day, when leaving his bungalow at Coremia in Assam, he met one of these Spiders coming up the steps, and on his approach the beast reared itself up, waved its legs, and hissed at him. And lastly, Prof. Baldwin-Spencer has made similar observations upon an allied genus Phlogius, observed by him in Australia, his account being accompanied by a beauti-