Page:The Zoologist, 4th series, vol 3 (1899).djvu/328

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302
THE ZOOLOGIST.

of Amphibia in an evolutionary sense is quite sufficient to account for it. This prompts two reflections: one that we ought to look a long way back for the origins of these protective and mimetic guises; and the other, that we may reasonably hope to find them. The present attitude of many champions of the cause, who seek to find, or to invent, present factors for producing these phenomena, seems fraught with peril for the whole theory; and with the same weariness and perseverance with which the original promulgators thought out the doctrine, we must go on searching for further proofs, which will necessitate our appealing to the Cæsar of the past—the ever-growing science of palaeontology.[1] In this domain many similar problems still remain unsolved. In the old red sandstone of Scotland are abundant remains of fishes, such as Osteolepis, but the reason why these and so many other ancient creatures were enveloped or armed in coats of mail, or rather the antecedent factors provocative of the evolution, has not yet been discovered.

In taking leave of these protected Phasmidæ we will record two—and only two—testimonies to their imitative deception, one old and the other modern.

When Pigafetta visited the island of Palawan, he saw many wonders, and described one as follows. There "are found certain trees, the leaves of which when they fall are animated and walk. They are like the leaves of the mulberry tree, but not so long; they have the leaf-stalk short and pointed, and near the leaf-stalk they have on each side two feet. If they are touched they escape, but if crushed they do not give out blood. I kept one for nine days in a box. When I opened it, the leaf went round the box."[2] This may be taken as a strong, and, what is more, then unsolicitated, testimony to the efficacy of protective resemblance among insects. Linnæus, doubtless with the true inwardness in his mind, wrote:—"Anyone who happens to see, in the Indian

  1. Among the slow Lemurs or Galagos we find enemies of the Phasmidæ. Mr. Lydekker, though not giving his authority, writes: "Some of the smaller species will readily devour Locusts, and the peculiar leaf-like Mantides, or praying insects" ('Royal Nat. Hist.,' vol. i. p. 223); but as no fossil lemuroid forms are at present known anterior to tertiary times, these records do not affect our enquiry.
  2. "The First Voyage round the World by Magellan" (Hakluyt Society).