July 7, 1892] 



NATURE 



223 



Between 11.45 ^"d 12 the south-east octant of the outer halo 

 <red inside) was also visible. 



Until I o'clock the figure was practically circular, the inner 

 •space being remarkably free of colour, the blue of the sky assum- 

 ing an ashy grey tint. By 2 the figure was elliptical, the long 

 axis horizontal, and the halo not complete. The ellipticity in- 

 ■creased as thesun sank. Hence the visible part wa-; evidently 

 formed of the tangent arcs. No doubt the intense brilliancy near 

 noon was due to these arcs practically coinciding with the 

 ordinary halo, because of the sun's great altitude. 



J. Edmund Clark. 



4 Lome Terrace, Edinburgh, June 30. 



The Electric Current. 



During the thunderstorm last evening, in the middle of the 

 fcrilliant flashes which illuminated the south-eastern sky, 1 

 noticed the electric current assume the following remarkable 

 ibrm : — 



Burlington Fine Arts Club, 



17 Savile Row, \V., June 29. 



Edward Hamilton. 



Are the Solpugidae Poisonous? 



At a recent meeting of the Linnean Society (June 2), I had 

 the honour of exhibiting the jaws, claws, and hairs of a species 

 ■of Galeodes from Tashkend, in order to show certain peculiari- 

 ties, which perhaps throw light on the question as to whether 

 these animals are poisonous or not. 



Murray, in "Economic Entomology," says: "Their bite 

 is said to be venomous, and even dangerous, but proof of this 

 is wanting." 



It is, further, always the natives in both the Old and New 

 Worlds where this " spider " occurs who give it its bad reputa- 

 tion, and always the European immigrant or settler who either 

 -doubts or even positively denies it. 



In spite of the well-known fact of the persistence of ground- 

 less terrors in the minds of uncivilized peoples, I should still be 

 inclined to think that, in a case of this kind, which is one of raw 

 ■experience, the natives would probably be in the right. 



Dufour, in his monograph of the Algerian species {Mem. p. 

 a rinstittit de France, xvii.), after describing a serious case 

 arising from a Galeodes bite, having failed to find any poison- 

 glands or apparatus, leaves the mystery to be solved by others. 



Croneberg [Zool. Anzeiger, 1879) claimed to have discovered 

 the poison gland in a long coiled gland, which he says opens at 

 the tip of a lancet-shaped process at the junction of the palp 

 with its basal or maxillar portion. As far as I can make out, 

 this gland is the homologue of the coxal gland of the other 

 Arachnids. This would not preclude the possibility of its being 

 a poison gland. On the face of it, however, I should not expect 

 to find the opening of the poison gland in this comparatively 

 awkward place. In a creature so armed for attack as Galeodes, 

 one would expect the venom to lake a more prominent place in 

 the offensive armoury. 



Examination, on immersion in clearing media, shows — 



(1) That the tips of the jaws are not only traversed by a 

 canal opening to the exterior, but are covered with multitudes 

 of fine pores, which can be traced with a low power through the 

 thick chitin. 



(2) The claws are also open at the tip, while the shaft of the 

 claw seems filled with a glandular mass of tissue provided with 

 tracheae. These claws are terrible weapons of offence ; the 

 articulating joint at the end enables them to anchor themselves 

 in the body of the prey. 



(3) Around these claws are sharp hairs, which appear, like the 

 claws, to be open at their tips. It is obvious that the tighter the 



NO. 1184, VOL. 46] 



claws draw themselves into the flesh, the deeper would the 

 pointed hairs at their base penetrate, and, if poisonous, increase 

 the deadly nature of the attack. 



(4) Leaving the spines on the limbs, and the long, thin appa- 

 rently tactile hairs out of account, the hairs on the legs and back 

 are, as a rule, forked at the tip, as has been already described by 

 Dufour. Up to the fork they are hollow, like those round the 

 claws. My suggestion is that these are like buttoned rapiers. 

 They are harmless until the animal is seized. The fork prevents 

 the hair from penetrating until the pressure is great enough to 

 snap ofT the tip. Small mammals and birds would soon learn not 

 to try to chew up or swallow a Galeodes. If this suggestion is 

 correct, the action of the forked hairs may be compared with that 

 of the stinging hairs of the common nettle. 



(5) Here and there are long hollow hairs, with the tips swollen 

 out into a thin bubble-like expansion of the chitin. These hairs 

 may be abnormal. I found five or six in all, and chiefly on the 

 palp. They seem to indicate a tendency of fluid to flow down 

 the hairs. 



The openings at the tips of the claws are quite in keeping, mor- 

 phologically, with those at the tips of the hairs. Claws are 

 but highly developed hairs. The jaws, however, are modified 

 joints of limbs. We have, therefore, to interpret the central 

 canal (?) and the pores which open at and around their tips, as the 

 canals which run through the cuticle into the hairs. We find that, 

 as we recede from the tips of the jaws, the open pores cease, and 

 the hairs commence, each with its central canal continued through 

 the cuticle. 



As to the nature of the poison which I suggest flows through 

 these apertures, I am inclined to consider it, in the presumed 

 absence of specialized glands, as a product of the hypodermal 

 cells, perhaps even of those which secrete the hairs themselves. 

 At the tips of the jaws, where the hairs have disappeared and 

 only their pores remain, these cells could be specialized for this 

 purpose alone. In the claws there seems to be a mass of cellular 

 tissue, which would also be a derivative of the hypodermis, and 

 may be solely taken up with the secretion of poison. 



One other point remains to be mentioned, viz. the mechanism 

 for the movement of the end joint of the claw. Articulated 

 hairs are common among the Polychaste Annelids, but the exact 

 mechanism is not visible. This large claw of Galeodes may ex- 

 plain these cases. We should naturally not expect a muscle fibre 

 in a hair. The actual mechanism is very simple. Along one side 

 of the claw the chitin splits, for, say, three-fourths of its proximal 

 length, to form an inner and an outer layer. A very slight differ- 

 entiation of the flexor muscles of the claw would allow of a few 

 fibres being attached to the inner layer. A pull at the inner strip 

 of chitin bends round the tip of the claw, invaginating a small 

 portion of the outer layer, which thus forms a collar round the 

 baseof the joint or "nail" as some call it. The bending of the 

 claw would almost necessarily compress its fluid contents, some of 

 which might escape through the opening at its tip. 



Until the question as to the poisonous nature of Galeodes has 

 been experimentally settled, these observations seem to have some 

 weight in the affirmative scale. Henry Bernard. 



Streatham. 



Death from Paraffin, and Members of Parliament. 



Notwithstanding the enormous development which has 

 taken place in recent years in gas and electricity, there can be 

 no doubt that oil lamps light the homes of a larger number of 

 persons throughout the world than any other illuminant. Even 

 in the United Kingdom alone it has been estimated that over 

 10,000,000 lamps are in use. No wonder, then, that newspaper 

 readers are every now and again startled by the recital of terrible 

 accidents, too often resulting in agonizing death. Mr. Alfred 

 Spencer, of the London County Council, stated at the inquest 

 on the late Lord Romilly that he estimated that there were 300 

 deaths a year caused in this country by unsafe lamps. Mr. Shean, 

 of the Fire Brigade Association, expressed the opinion that 10 

 per cent, of fires are caused by paraffin lamps ; and Captain 

 Shaw, the former Superintendent of the London Fire Brigade, 

 reported 156 fires in one ye.ar caused by the upsetting of lamps 

 in London. Will a friend to humanity in each constituency ask 

 the candidates, whether Liberal or Conservative, to pledge them- 

 selves to support a short Act of Parliament compelling every 

 lamp to have affixed to it an automatic extinguisher, as recom- 

 mended in the reports of Sir Frederick Abel, Mr. Boverton 

 Redwood, and Colonel Majendie, or must we wait until a Bishop 

 or a Royal Princess is burnt to death ? Humanity. 



