HARDWICKE'S SCIENCE-GOSSIP. 



9i 



ZOOLOGY. 



Motion in Spider's severed Leg. — The 

 " spider " referred to under the above heading, in 

 ■"Science-Gossip" for March, 1885, p. 69, was in 

 all probability one of the Phalangiidaj or harvest-men, 

 not a true spider. Harvest-men, especially those of 

 the genus Liobunus, throw off their legs voluntarily 

 and with great facility, but never, so far as I am 

 aware, unless the leg is in a captive state. The leg 

 thrown off will continue to move for some little time, 

 its muscular power and nervous sensibility being 

 very great. Escape is doubtless the motive on the 

 part of the harvest-man, but whether any idea of 

 drawing off the attention of the enemy, by means of 

 the motion of the cast-off leg, is mixed up with that 

 motion, seems improbable. True spiders, especially 

 those of the genus Clubiona, will also throw off their 

 legs, but they appear to require a greater purchase to 

 enable them to do so than the Phalangids, and their 

 legs when severed have not nearly the same amount 

 ■of motion. I have always found that if a spider be 

 held by two of its legs it cannot obtain the necessary 

 purchase, and so cannot throw off the limb. It is 

 •quite true that the spider, or harvest-man, suffers, 

 apparently, a minimum of inconvenience in the loss 

 of a leg or two, but there must certainly be a 

 •considerable drain on the system as the stump always 

 bleeds freely. I once saw an example of Liobunus 

 rotundus running with very fair speed, and in wonder- 

 fully steady time, having only three out of its eight 

 legs remaining. — O. P. Cambridge, Bloxwortk 

 Rectory. 



Melanic Variation in Lepidoptera. — In his 

 presidential address to the Yorkshire Naturalists' 

 Union, " On some probable causes of a tendency to 

 Melanic Variation in Lepidoptera of high latitudes," 

 Lord Walsingham remarked that northern representa- 

 tives of southern forms of lepidoptera showed a 

 tendency to assume a darker or more suffused colour, 

 the same tendency being observable in those 

 frequenting high mountain ranges, and he discussed 

 various reasons which have been suggested to account 

 for such phenomena. He supposes it to be, perhaps, 

 due to the advantages derivable by the insect from its 

 being able the more rapidly to absorb invigorating 

 warmth ; and also to surplus vital energy leading to 

 the deposition of pigment. He pointed out also that 

 though the same darkness of colour would cause a 

 more rapid loss as well as gain of heat, this would 

 not be of so much consequence in the case of insects, 

 while in the case of the power of dark races of 

 mankind to support tropical climates, the tendency 

 of the darker skin to absorb heat would be compen- 

 sated by the quicker loss of the same. 



Another attempt to carry humble-bees to New 

 Zealand to fertilise the clover has failed. All the 

 insects were found dead when the case was unpacked. 



BOTANY. 



Cocain in Different Species of Erythroxy- 

 lon. — A grain of cocain, from the South American 

 tree Erythroxylon Coca, has been selling in London 

 up to three shillings and sixpence as a retail price, 

 and the Secretary of State for India has forwarded to 

 the Government of India a letter from Surgeon- 

 General Balfour, suggesting that the plant should 

 be introduced into that country. Surgeon-General 

 Shortt has been asked to ascertain whether similar 

 properties to those possessed by E. coca, may not 

 be found in some of the East Indian species. Sir 

 Joseph Hooker's " Flora Indica " enumerates seven 

 species there : E. Burmanicutn ; E. Kunthianum ; 

 E. lauceolatum ; £. lucidum ; E. monogynum ; 

 E. obtusifolium and E. sideroxyloidcs. 



The Edelweiss. — So favoured by legend and 

 romance, the edelweiss is worth cultivating, and 

 this is easily done. It is rather a new introduction to 

 our florists' catalogues, but every lady may soon 

 have it in her drawing-room, if she wishes. It will 

 flower almost as well in town as in country, at least 

 under glass. I got some seed of Freeman's, of 

 Norwich, two years ago ; and, sown early in spring in 

 a flat pot, with sandy peat and good loam, and kept 

 moist, it vegetates in a fortnight, and must then be 

 pricked out, and put in a cool frame, and then 

 planted out of doors in about six weeks. It takes as 

 much sun as can be given it. The above are the 

 nursery directions, and, having followed them, I 

 raised some nice plants. Any lady who wishes to 

 emulate the brides of Switzerland has only to order 

 her gardener to sow the seed, and the edelweiss may 

 be ready for the boudoir or the hair in a few weeks, 

 as easily grown as forget-me-nots. The mystery of 

 the edelweiss may be then studied at leisure, as long 

 as it continues flowering, or it may be put into an 

 album or herbarium when it has ceased to do so. — 

 John Emmet, F.L.S. 



Fertilisation of Geraniums.— The following 

 observations on Geranium plueicm and G. sanguineum 

 may be of interest : — At an early stage of inflo- 

 rescence the pistil is surrounded by the anthers in 

 such a manner that if the pollen was shed, and the 

 stigma ready to receive it at the same time, self- 

 fertilisation would be inevitable. After the pollen is 

 shed, the anthers fall off and the filaments turn away 

 from the style. Then the stigma opens out and 

 shows its five-cleft form, ready to receive the pollen- 

 grains which may be brought by bees from other 

 flowers. Afterwards it closes again and remains so. 

 — G. W. Bulman. 



Blossoming of the Artichoke. — The flowering 

 of this plant appeared to be general in Middlesex, 

 last autumn. Our crop here, in N.W. Middlesex, 

 was much liner than usual, and nearly every plant 



