SCIENCE-GOSSIP. 



2 33 



the glass jam-bottles, in which I keep small 

 specimens, which were on a shelf at entrance of 

 the summer-house, were not only coated but lined 

 with ice. In some cases the creatures, such as 

 Corixa notonccta, etc., were frozen to the ice at 

 the sides of the bottle. I removed the ice and 

 strangely enough, none of my frozen creatures 

 died. The next few nights I placed coarse green 

 tarlatan over the aquaria, and slight as the 

 protection was no more ice was formed. We have 

 now in the garden a pair of squirrels and a pair of 

 nut hatches, both squirrels and birds have hoards 

 of nuts in a grass bank of some three feet high that 

 borders a rose bed. These they visit continually, 

 and the nut hatches have found a convenient cleft 

 in one of the cedar-trees close by in which they 

 place the nuts to hammer with their strong beaks. 

 Under the tree is quite a large litter of nut-shells, 

 and as they are mainly American cob-filberts 

 coming from our nut walks, which are much harder 

 than ordinary hedge-nuts, the strength of a nut- 

 hatch's bill can be readily appreciated. 



On November 14th two tiny water-spiders 

 appeared for the first time in one of my bottles 

 in which some duckweed lies on the surface. I 

 look upon duckweed as a real mater genitrix of all 

 sorts of creatures, for as sure as one places some in 

 a bottle of water and leaves it alone, will something 

 or other appear from it, and for weeks, aye. 

 months, one may, each few days, see something 

 evolved from it afresh. As I do not think my very 

 simple small aquaria jars are commonly kept by 

 nature lovers, I may state that unless they contain 

 creatures that require feeding I seldom empty 

 them, and only occasionally put a little water in 

 to freshen and replace the waste from evaporation. 

 If I wish to exchange the water without disturbing 

 the inhabitants I place a piece of fine Brussels net 

 over the bottle and carefully pour away what I 

 wish, the net preventing loss of any perceptible 

 object. 



My old water-spider which lives in a glass to 

 himself, together with the two babies in their 

 separate glass are at this time of year very coma- 

 tose, and close themselves tightly in an air bubble 

 amongst the weed. In fact, yesterday I thought 

 one of the little ones had disappeared, but on 

 taking out a sprig of anacharsis I found him 

 tightly fastened into a fold of a leaf. On being 

 taken out he assumed the lovely grey bloom, 

 like a plum, that a water-spider presents on being 

 removed from the water. 



Water-spiders which are caught at the same time 

 will live occasionally in amity, but seldom if caught 

 at different times, the elder inhabitant deeming 

 fresh arrivals intruders. My spiders' commissariat 

 is furnished by mixing with the river-water some 

 stagnant water containing Daphnia cypris, and 

 other small fry, also, when plentiful, a few dead 



K 



flies, earwigs, etc., for the large spiders; the litt'e 

 ones apparently feed on creatures too small to be 

 seen by the naked eye. 



Shiplake, Oxon.; November, 1895. 



GALVANOMETER SCALE AND 

 LAMP. 



A NEW galvanometer scale and lamp has been 

 ■**■ patented by Mr. James J. Hicks, of London, 

 upon Burstall's invention. We have had an oppor- 

 tunity of examining the instrument, which is 

 remarkable for its portability and convenience for 

 packing. The chief feature is that this instrument 

 works with perfect facility either in daylight or in 



- - 

 Burstall's Galvanometer Scale and Lamp. 



a brightly illuminated room. The focussing tube 

 is carried on a ball joint. By means of a sliding 

 tube it can be set at any required height, and when 

 the exact point has been attained, the movable 

 points can be locked, when focussing proceeds 

 without fear of the spot moving on the mirror. 

 The scale is divided in millimeters, and can be 

 adjusted both vertically and horizontally. The 

 source of light is a small incandescent lamp, 

 worked by storage batteries ; a fine line is etched 

 on the object glass, and this line is focussed on 

 the scale. The instrument constitutes a marked 

 advance on anything of the kind hitherto produced. 

 Its cost is £10 7s. 6d., with accumulator and 

 extra lamp. 



Reversed Helix hispida. — In the October 

 number of " The Annals of Scottish Natural His- 

 tory," Miss Janet Carphin, of Edinburgh, records 

 the discovery, in July last, in Berwickshire, of a 

 reversal specimen of H. hispida, which she thinks 

 is unique, at least as no mention occurs of the var. 

 sinistrorsum for that species in the Conchological 

 Society's " List of British Land and Freshwater 

 Mollusca." 



