2l8 



SCIENCE- GOSSIP. 



Notes z 





JUERIE} 



Japanese Waltzing Mice. — Can any of your 

 readers give any explanation of the remarkable 

 behaviour of Japanese waltzing mice, which con- 

 tinually spin round and round for hours together 

 in their cage ? I should be glad also of any 

 information as to their natural condition. — W. J. 

 Pinchney, St. Leonards-on-Sea. 



Photography v. Drawing. — At the close of a 

 lecture before the South London Natural History 

 Society on November 14th a discussion arose on 

 the respective merits of photographs and drawings 

 for the portrayal of natural history objects. The 

 question is of the greatest importance, and one 

 whose consideration is worth the attention of all 

 who may wish to illustrate scientific publications 

 or lectures. As my efforts have been chiefly 

 directed toward the elucidation of the structure 

 and habits of the Araneidea, I think that I had 

 better base these remarks upon that order. Fcr 

 convenience we will consider only the case of 

 workers possessing equal capabilities both in 

 photography and drawing. In the first place, for 

 systematic work intended to facilitate the identifica- 

 tion and classification of natural objects, accurate 

 drawings are absolutely necessary. Photographs, 

 if not useless, are of little value without diagram- 

 matic details. In support of this opinion I may 

 state I have never published a photograph of 

 scientific details, although such a procedure 

 necessitates far less labour than the preparation of 

 line drawings. The field naturalist, however, is 

 constantly brought face to face with occurrences, 

 possibly habits inherent to a species, perhaps 

 merely incidents, which may or may not be 

 of scientific value. The delineation of such 

 phenomena would absorb a very considerable, 

 and indeed almost unjustifiable, amount of the 

 time at the disposal of the worker desirous of 

 acquainting himself with the general structure of 

 the representatives of a natural order. The habits 

 of many of these creatures, however, are of absorb- 

 ing interest, and their consideration undoubtedly 

 tends to detract from the possibilities of a study 

 drifting into the depihs of abysmal obscurity, and 

 of its devotees becoming mechanical and soulless 

 slaves to rules and systems. Here photography 

 comes to the rescue, not only as a recreation, but 

 as a means of arousing interest in the minds of 

 other individuals who might, perhaps, in years to 

 come, develop those studies which are in their 

 infancy. Another phase of scientific photography 

 whiGh was discussed was the production of photo- 

 micrographs. The necessity of employingartiricially 

 flattened preparations is, I agree, a most serious 

 disadvantage, but even these reprehensible pro- 

 ductions are not without their uses. In the study 

 of the tarsal claws of spiders crushed prepara- 

 tions are of great value, and the relative length of 

 the joints of the legs may be measured with the 

 greatest facility from photomicrographs. This 

 method not only involves a considerable saving of 



time, but is an incalculable relief to the eyes of 

 the busy arachnologist. One further point deserves 

 a passing notice. The methods most suitable for 

 lectures may not be thoroughly satisfactory for 

 deep research. A lecture upon a neglected group, 

 delivered before an audience of whom perhaps 

 seventy-five per cent, have already specialised in 

 other studies, and most of the remaining twenty- 

 five per cent, will never enter upon any systematic 

 investigation, should be more or less of a popular 

 nature. Especially should this be the case if the 

 lecturer announces his willingness and desire to 

 help a beginner along the seldom-trodden and 

 labyrinthine paths of the study to whose interests 

 his own life-energies are devoted. — Frank P. Smith, 

 15 Cloudesley Place, Islington, London. 



Ice Discs on Leaves. — At the beginning of 

 November there were four days of very thick fog, 

 with several degrees of frost each night. During 

 the day a heavy continuous dropping of the con- 

 densed moisture of the fog w T as taking place under 

 trees. The ground was perfectly dry in places 

 exposed to the sky, but exceedingly wet under the 

 canopy of foliage. Where trees overhung the roads 

 the amount of water deposited became so large 

 that when there was a slight incline it overflowed 

 the dry, dusty portion as a rivulet until it reached 

 the ditch. The roads were thus banded with dry 

 and muddy belts One afternoon during this time 

 I observed a curious phenomenon beneath some 

 hedge-row elms. The road was carpeted with 

 their fallen golden leaves, about half of the year's 

 foliage still clinging to the trees. As I approached 

 I saw that there were strewn irregularly here and 

 there over the surface of the ground a large number 

 of white objects. They were roundish, and from 

 \\ to 2 inches in diameter. The appearance was 

 as if a quantity of small white poplar leaves had 

 been scattered over the surface. My curiosity 

 was aroused at the sight, and when I came 

 up to the spot I saw that these remarkable 

 disc-like objects were in reality lumps of ice. 

 They were formed of clear transparent ice about 

 one-eighth of an inch, thick and were exactly 

 the size and shape of the elm leaves. The con- 

 densed fog had accumulated as a layer of water on 

 some of the leaves on the trees that were in a 

 suitable position for such an occurrence, and had 

 frozen on to them dudngthe night. The next day 

 a slight rise in the temperature must have loosened 

 the ice discs from the leaf, and they floated un- 

 broken to the ground, alighting on the strewn leaf- 

 carpet. The leaves on which they had grown may 

 have descended at the same time, but the prostrate 

 discs were dissevered from them, lying quite loosely 

 on their amber couch. The farmer at whose door 

 the phenomenon was occurring had also observed 

 the strange flight, and remarked how " the ice be 

 a-comin' doon from the trees." An event such as 

 this may not be uncommon on the needles of 

 conifers or other evergreen leaves, though I do not 

 recollect having heard of it, but I am inclined to 

 regard it as unusual when taking place on a 

 deciduous-leafed tree. As a rule the leaves will 

 have already fallen from such trees before we enter 

 the climatic conditions which render this feat 

 possible ; but fogs and frost set in with sudden and 

 early severity this year. It will be interesting to 

 hear if notes on ice discs reach you from other 

 parts of the country, as the fog spread over a large 

 area. — (Mrs.) I. J. Arm.itage, Dadnor, Hereford- 

 shire, November 9th, 1901. 



