Page:Hardwicke's Science-Gossip - Volume 1.pdf/213
in the other instance (of Sagartia and Bernhardus), the Anemone seems only to recognize the Crab, and not the Crab to be conscious of the Anemone; for even when Bernhardus has been burdened with three S. parasitica on its shell at one time, I have never seen it seem more anxious to change its shell than when it has only a shell alone to carry. In further proof of this recognition being natural in the one case, and one-sided in the other, I have to state that though I have had brought me many thousands of the common Hermit Crab (P. Bernhardus) without any Anemone (S. parasitica), I have never got a single specimen of the less common Hermit (P. Prideauxii) without its special Anemone (Adamsia palliata). I also have to observe that the manner in which P. Prideauxii assists the transfer of Adamsia from one shell to another, reminds one exactly of the manner in which a person would remove and then re-fix a sticking-plaister to his or her chest, first loosening and picking it away at the edges, and then gradually peeling it off entirely, and afterwards broadly applying a new plaister with both hands, smoothing and working it down in places, and taking particular care in making it adhere firmly all round the margins. The action is all the more suggestive because the relative positions of a man's hands, arms, and chest correspond with much precision to the relative positions of the two first (right and left) legs of the crab, and to the part of his shell to which he desires to affix the Anemone.
Has any one ever seen a very small specimen of Sagartia parasitica, or of Tealia crassicornis;—as small, I mean, as the young ones of any other common Sea-Anemone? I never have; and the least of those two species which I recollect to have observed, was as large when close, as a small cherry.
W. Alford Lloyd.
Zoological Gardens, Hamburg.
MORE NOTES ON THE HAIRWORM.
Weary and dusty, after several hours' work among the flint and chalk on the new line of railway between Walden and Wenden, I began my way home. To escape censure for looking like a bricklayer's labourer, and not wishing to offend the public taste, I threw my bag of fossils on the bank of the classic Cam, which, at midsummer, is here a mere stream, and sought by water to cleanse me from offence. Amid my cooling ablutions, two hairworms attracted my attention, which I immediately captured, placed in a piece of paper, and carried home in my waistcoast pocket, to examine at my leisure.
This worm was the subject of a brief but interesting paper at page 107. It belongs to the Nematoid order of Entozoa, and bears the name of Gordius aquaticus. Would not the kingly spirit who once ruled in the flesh over the Phrygians feel himself humbled that his name should be mortalized in such a worm? That is, if spirits wander and wonder at all. This worm, no doubt, got its name from the extraordinary manner in which it knots itself, and is thus supposed to resemble the leather harness of Gordius, which was so intricate that there was no finding out where it began or ended.
One of my humble acquaintances measures no less than 8 inches in length. It has no jointed skeleton internally, but a jointed covering, as in insects. It is said that these creatures live a parasitic life in the body of some unfortunate insect, of an astonishing small size when compared with the great length of the worm. When mature they quit the body of the insect at whose expense they have lived, for some moist place or watery spot, to deposit their ova, which is accomplished in long chains. It has been stated of this species, that, on quitting its parasitical home for a terrestrial habitation, should it find dry weather—a state of things by no means congenial to its nature—it will shrink up into a perfectly hard and dry substance, and wait for a more favourable season. These worms draw their nourishment for the support of their bodies through the skin by absorption. I removed one of my specimens from its aquarium, which I had extemporized in a tumbler, and subjected it to a scorching mid-day sun. It soon adapted itself to altered circumstances, and what was a few minutes before a round-bodied, graceful worm, grew flat, rough, and contracted; slowly knotting itself till at last it became small and motionless, and blown about by the faintest breath of air. Satisfied that it had undergone sufficient scorching, if possible to deprive it of life, and of ever again sporting its hair-like body in my glass, I returned it thither again after about three hours' exposure to the sun's rays. You will not wonder that I watched it with an earnestness that would have done honour to a more weighty matter, as it absorbed moisture and gave off little air-bubbles from almost every joint. It gradually assumed its former shape, gave signs of life, and, to my no small joy, soon sported its long body with becoming jollity at being restored—if not to life, at least to the element more compatible with its notion of comfort. The figures represent the head (a) and tail (b) of female magnified.
Some weeks after the above event I revisited the spot, and found the little water that remained apparently alive with these small creatures. The water-