I04 



NATURE 



[June i, 1893 



close by, similar swarms were to be seen. Even these, however, 

 were inaccessible ; but I caught some of an apparently similar 

 swarm drifting over the ground between the bushes, and in- 

 close some of the specimens herewith. To me they look just 

 like the insects which ordinarily strew one's table under the lamp 

 at night (I notice, by the way, that to-night there are none, 

 though the window is open as usual), and therefore I am 

 led to suppose that the special character of the swarms noticed 

 to-day appertains to some condition of the atmosphere, and not 

 to the species of insect ; but perhaps some of your contributors 

 can throw light on this point. It would also be very interest- 

 ing to know whether similar swarms were noticed elsewhere 

 to-day, and whether they showed the same slant as was noticed 

 here. R. E. Froude. 



Admiralty Expt. Works, Haslar, Gosport, May 27. 



P.S. — The swarms of flies disappeared about I p.m., as the 

 thunder clouds cleared away. 



Popular Botany. 



We do not expect accurate scientific information from journ- 

 alists ; but so much confusion and error are seldom com- 

 pressed into a small space as are to be found in a paragraph of 

 which I send you extracts, cut from a London daily : — " A sad 

 case of accidental poisoning by wild hemlock is reported from 

 Tyne Dock. A little band of school children playing on some 

 waste ground had gathered a quantity of a common variety of 

 this dangerous plant, known to country folk as 'fool's parsley.' 

 According to the evidence of one of the party, a little girl aged 

 eight named Pringle, her sister 'said it was cabbage, and she 

 should eat some.' Another boy and girl, named Shafter, who 

 were still younger, followed her example. All three were soon 

 afterwards taken ill. One ' complained of her legs as if they 

 were tired' — -a common symptom of hemlock poisoning — and 

 ' her head afterwards got bad.' Pringle ultimately recovered 

 under treatment, but the two Shafters on reaching home gradu- 

 ally became unconscious, and died the same afternoon within 

 twenty minutes of each other. This species of hemlock, known 

 to science as the Conium maculatHm, is said to be much more 

 poisonous in May than in any other month." It would be 

 interesting to know what the plant really was. It can hardly 

 have been the true hemlock, Conium macidatum, and instances 

 of fatal poisoning by fool's parsley, Aethtisa cynapUtm, are so 

 rare that an authentic record would be valuable. It is difficult 

 to imagine either of these plants being mistaken for cabbage. 

 Can it have been Cictita virosa or Oenanthe crocata ? It would 

 be interesting if any reader of Nature could throw light on 

 the subject. 



The following delightful paragraph is cut from the same paper 

 a few days later : — 



" Can plants see ? Darwin gave it as his opinion that some 

 of them can [one would like to know where], and an Indian 

 botanist relates some curious incidents which tend to verify the 

 belief. Observing one morning that the tendrils of a convolvu- 

 lus on his verandah had decidedly leaned over towards his leg 

 as he lay in an attitude of repose, he tried a series of experiments 

 with a long pole, placing it in such a position that the leaves 

 would have to turn away from the light in order to reach it. J n 

 every case he found that the tendrils set themselves visibly towards 

 the pole, and in a few hours had twined themselves closely round 

 it." 



Alfred VV. Bennett. 



Gaseous Diffusion. 



In your Notes of last week there is a description of an experi- 

 ment for showing gaseous diffusion, devised by Prof v. 

 Dvorak, which, however, does not seem so striking as one that 

 was shown at the Royal Institution more than twenty years ago 

 by, I think, Dr. Odling. 



A cylindrical porous battery cell was closed by a cork through 

 which passed a vertical glass tube of about half an inch in 

 diameter. The lower end of the tube was bent upwards into 

 the form of a delivery tube, and was placed in a pneumatic 

 trough, with a cylinder filled with water inverted over the end 

 of the tube. On placing an inverted bell-jar of hydrogen over 

 the porous cell, gas was rapidly collected in the cylinder, and 

 this contained sufficient hydrogen to explode on the application 

 of a flame. On removing the bell-jar, the hydrogen diffused 

 outwards, and water was drawn up the wide tube. 



Cooper's Hill, May 29. Herbert McLeod. 



NO. 1 23 1, VOL. 48] 



NOTES UPON THE HABITS OF SOME 

 LIVING SCORPIONS. 



'X'HE literature which treats of the habits of living scor- 

 ■'■ pions is not voluminous, but it labours under the 

 disadvantages of being based largely upon undetermined 

 species, and of being often of questionable trustworthi- 

 ness with regard to the statements that are made. 

 Even accounts that have been given of late years of the 

 same species of scorpion differ widely as to facts of no small 

 importance. Mons. L. Becker, for instance, asserts that 

 the senses of hearing and seeing are highly developed in 

 Prionurus australzs, the thick-tailed yellow scorpion of 

 Algeria and Egypt ; Prof. Lankester, on the contrary, 

 declares exactly the opposite to be the case. Dis- 

 crepancies such as these and the deficiencies above 

 mentioned show the need for fresh observations upon the 

 subject, and no further excuse need be offered for publish- 

 ing the following notes upon the habits of some speci- 

 mens of two species of scorpions, Parabuthus capensis 

 and Euscorpius carpathicus, which I was fortunate 

 enough to keep for some months in captivity. 



For the specimens of Parabuthus I gladly take this 

 opportunity of expressing my thanks to my friend Mr. 

 H. A. Spencer, of Cape Town, who kindly collected them 

 for me at Port Elizabeth, while acting as medical officer 

 on board the Union Steam Ship Company's s.s. 

 Mexican; while for the Euscorpius I am indebted to the 

 kindness of Dr. Gestro, of the Natural History Museum 

 at Genoa. This last genus of scorpion Prof. Lankester 

 has also written about ; many of my observations, there- 

 fore, merely confirm those of this author. No descrip- 

 tion, however, has to my knowledge ever been published 

 upon the habits of any species of Parabuthus. This 

 genus, however, belongs to the same family as Prionurus, 

 and the behaviour of the two in captivity seems to be 

 very similar. 



There is an abundance of evidence that scorpions are 

 nocturnal, and mine were no exception to the rule. They 

 wotild spend the daytime huddled together in corners of 

 their box or under pieces of wood ; at night they would 

 wander about, presumably in search of food. It was 

 easy, however, at any time during the day to rouse them 

 from their sluggishness by applying a little artificial 

 warmth to the box. One end of the box containing the 

 Parabuthus was closed with a plate of perforated zinc. 

 If this box was placed in the fender at a distance of about 

 a couple of feet from a moderate fire, with the zinc end 

 turned towards the grate, the scorpions would climb upon 

 the metal plate and bask in the warmth. But im- 

 mediately the box was brought near the bars of the grate 

 they would all clamber or tumble from their position with 

 ludicrous haste. It must not be supposed, however, that 

 the amount of heat required to make them retreat was 

 at all great. As a matter of fact warmth that I could 

 without inconvenience bear for several minutes upon my 

 hand would throw these animals at once into a state of 

 the greatest consternation. 



When walking both Parabuthus and Euscorpius 

 carry the large pincers or chelje well in advance of the 

 head ; these appendages thus fulfil the office of antennae 

 or feelers. In Parabuthus the body, however distended 

 and heavy with food, is raised high upon the legs exactly 

 as Prof Lankester has described in Prionurus, and the 

 tail is usually carried, curled in a vertical plane, over the 

 hinder part of the back. In Euscorpius, on the con- 

 trary, as has also been pointed out by Prof. Lankester, 

 the ventral surface of the body is scarcely raised from 

 the ground during progression, and the tail, which is very 

 slender and relatively much lighter than in Prionurus or 

 Parabuthus, is dragged along, extended, and with a slight 

 curl only at its hinder end. This difference in the car- 

 riage of the tail depends possibly upon the ditterence in 

 its size and weight. For it seems reasonable to suppose 

 that the heavy, robust tail of a Parabuthus or Prionurus 



