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SCIENCE-GOSSIP. 



perfectly hysterical with fright, so one of us stowed 

 away the frightened bundle of fur under his coat 

 and carried it home, to be comforted, fed, and set 

 once more at liberty. We found that the polecat 

 had seized her prey by the eyelid. This is generally 

 the point of attack, and one can well imagine the 

 agony of the victim whilst a cruel monster is 

 endeavouring to get at its brain, first of all tearing 

 away the eyeball and devouring it. Sometimes 



the brain is reached from immediately between the 

 ears, more rarely through the orifice of the ear 

 itself. Such, then, is a brief history of this 

 representative of the weasel family, which, accord- 

 ing to rustic belief, fascinates its victim with its 

 piercing gaze, thus bringing on a hypnotic trance, 

 during which the medium is incapable of self- 

 defence. 



Llandyssul ; January, 1895. 



LARVA-NYMPH OF BRACHYTRON PRATENSE. 



By W. J. Lucas. 



T T THY such gorgeous and fascinating creatures 

 as the dragon-flies are not more generally 

 sought after by entomologists seems somewhat 

 inexplicable, since, of course, naturalists do not 

 share the popular prejudice which arms the insects 

 with a sting. The reason why the larva-nymphs 

 should meet with neglect is perhaps not so far to 

 seek, for they have little beauty of colouring or 

 grace of movement that we can admire, and their 

 habitat is usually as unsavoury as it is inaccessible 

 — the mud and decaying vegetation of stagnant 

 ponds and slow-running streams. A closer ac- 

 quaintance with these peculiar early forms of the 

 Odonata will, however, speedily awaken a lively 

 interest in anyone who will take the trouble — if 

 trouble it is — to rear them. To such a one the 

 following short note on the last stage of .the nymph 

 condition of Brachytron pratense , Mull., will perhaps 

 be interesting. 



On March 23rd, 1894, while searching over some 

 dead sticks, taken from the Basingstoke Canal, 

 near Byfleet, in the county of Surrey, with the hope 

 of discovering on them the fresh-water limpet 

 (Ancylus lacustris, Linn.), specimens of which had on 

 a previous occasion been secured by this means, I 

 found several larva-nymphs of some ^Eschnine 

 dragon-fly, of whose identity I was uncertain. Being 

 of the same sepia-brown tint as the dead sticks, and 

 resting with their bodies closely adpressed to 

 them, the insects were extremely well protected 

 from casual, as well as from close observation. 

 Even when the sticks that bore them were held in 

 the hand, they might have been, and indeed were, 

 passed over as pieces of loose bark or something of 

 that nature. It would be interesting to know 

 whether this " protective resemblance " was 

 offensive or defensive — whether, that is, the insects 

 were lurking in search of prey or themselves hiding 

 from some dangerous enemy. If the truth were 

 known, the former would probably turn out to be 

 the case. 



Unfortunately but half-a-dozen specimens were 

 taken, these being placed in a sandwich-tin with 

 some moss. An hour or so later a boggy spot was 



passed and here the moss was replaced by a 

 quantity of wet sphagnum, in which the insects 

 remained without taking harm from about mid-day 

 till quite late at night, when they and the sphagnum 

 were placed in water. The fact that they will live 

 thus out of water, so long as they are kept damp, 

 suggests a very convenient method of sending 

 larva-nymphs through the post. 



Having no living provender with which to supply 

 my captures, I tried small pieces of white of egg 

 and meat, but these they treated with disdain. In 

 consequence they remained almost without food 

 until April 4th, before which date one of their 

 number had been killed and partly eaten by its 

 fellows. On April 4th, I obtained and gave them a 

 number of fresh-water shrimps (Gammarusfluviatilis), 

 and it was not many minutes before two at least 

 had caught one each and commenced devouring 

 them with evident relish. Indeed no food was 

 taken so readily as these little. Crustacea, which 

 are easily obtained from any briskly running pebbly 

 brook and are no less easily kept alive to assuage 

 periodically the ravenous appetite of the youthful 

 dragon-flies. I several times watched a capture. 

 The hungry nymph did not attempt to hunt down 

 its prey, but remained perfectly still and waited 

 till a shrimp passed within striking distance of its 

 formidable claw-like lower jaw. If the stroke was 

 successful, notwithstanding its struggles, the 

 shrimp was at once made a meal of. If not, the 

 wily hunter remained as before perfectly still, till 

 another passed, when perchance a more successful 

 stroke was made. So suddenly is the jaw shot out 

 and returned that an onlooker is not able to make 

 out its shape. 



I once thought I would give my prisoners a treat 

 by supplying them with some lively young tadpoles. 

 Several were soon caught, but after being held for 

 a short time were invariably set free, their captors 

 seeming by their actions to show feelings of dislike. 

 Tadpoles as food have been suggested, and possibly 

 all dragon-fly nymphs may not be equally fastidious. 

 I ought to say, however, that the tadpoles after- 

 wards disappeared and may have been eaten after 



