HARDWICKE'S SCIENCE- GOSSIP. 



217 



lines are not continuous; that the markings cannot 

 be detached without destroying the scale ; and that 

 those scales that had the appearance of being 

 rubbed were impregnated with some oily or fatty 

 matter, probably exuded from 'the body of the 

 insect. AVe have found the following to be the best 

 plan for detaching the scales. After the insect has 

 died and become perfectly dry, double a piece of 

 smooth paper, place the insect close to the double, 

 fold it over and rub the paper with the finger-nail ; 

 open the paper, remove the insect, place the part to 

 which the scales are adhering on a thin cover, and 

 again rub it ; the scales will now be transferred to 

 the cover, and will be found free from oil or mois- 

 ture, and not injured by the process. This will also 

 be found the most effective way of detaching the 

 scales from the wings of butterflies ; by this means the 

 outer surface is placed uppermost, and the scales 

 from the upper and under surfaces of the wing will 

 occupy opposite halves of the cover. 



In a note to the chapter on Test Objects, Mr. 

 Pritchard makes the following remarks : — 



" When it is considered that these lines (those 

 on Podura and Pieris) are less than the twenty- 

 thousandth of an inch distant, it must be allowed 

 there is some difficulty in accurately determining 

 their construction. 



" The Morpho menelaus and Lepisma saccharina 

 are of sufficient size to distinctly perceive they are 

 composed of two delicate tissues with longitudinal 

 cords (probably tubular) disposed between them ; 

 but in the two delicate ones, the subject of these 

 remarks, we perceive other systems of lines dis- 

 posed obliquely, and as they are extremely delicate, 

 it becomes a question whether they actually exist, 

 or whether they are appearances produced under 

 certain modifications of the illumination. To 

 determine this point, it became necessary to ascer- 

 tain the cause which would produce such an effect ; 

 and it immediately occurred to me that these 

 oblique lines were occasioned by the disposition and 

 pressure of the superincumbent scales, in the same 

 manner as the watery or wavy appearance is 

 communicated to corded silks and moreens by 

 the pressure of two pieces passed between 

 rollers." 



(To be continued.) 



ON THE DISCOVERY OE MACROSPORES 

 I IN CARBONIEEROUS SANDSTONE. 



MACROSPORES of the Lepidodendroid plants, 

 or trees, have been described both by Mr. 

 Salter and also by Professor W. C. Williamson, of 

 Owens College, Manchester. The figures given by 

 each somewhat differ iu outline, but agree generally 

 in the rounded figure which the " spores " present 



in perspective. When the macrospores are flattene d 

 vertically, a triangular ridge appears in their centres — 

 " The flattened remnant of the angle resulting from 

 four spherical spores mutually compressing each 

 other so as to form a common spherical map, in the 

 centre of which all the four spores are in mutual 

 contact." * 



These macrospores have hitherto been found in 

 great abundance in the coal ; and whenever a verti- 

 cal section of coal has been cut, these "spores," 

 very much depressed, have formed a microscopic 

 slide very instructive to study. According to Wil- 

 liamson, their existence was pointed out by Henry 

 Witham more than half a century since, though he 

 was ignorant of their nature. 



On the 16th of April last, I paid a casual visit to 

 a carboniferous sandstone-quarry, worked for build- 

 ing purposes, in Wincobank Hill, Old Grimesthorp, 

 Sheffield. The sandstone is above the Parkgate 

 and Silkstoue seams of coal, which crop out below 

 the sandstone a short distance from the quarry on 

 the northern side. The sandstone is from eighty to 

 ninety feet in thickness, of variable texture, and 

 dips towards the east at an angle of about 40°. 

 Immense quantities of drifted calamite stems are 

 found lying in different directions in the quarry, 

 some of these varying in diameter from an inch to 

 ten inches, with lengths likewise variable from three 

 yards to two and three inches. Eor something like 

 seven years I have visited the quarry off and on, 

 securing specimens of the various species of caia- 

 mites as they turned up, but during the whole of 

 this time I have only secured two very indifferent 

 specimens of Lepidodendron. On the above date 

 1 was with a friend, trying to give his mind a geo- 

 logical turn by giving him a geological lesson. 

 When describing, in the lowest part of the quarry, 

 the action of the water-flow by the- position of the 

 calamite stems, my eye fell upon a most unusual 

 fracture in the stone. On examination, I found the 

 fracture, about three inches in length, filled with a 

 soft carbonaceous sandy material, which to me was 

 quite new. I scraped the whole into a paper, and took 

 a rough sketch of the spot until I could examine 

 the mixture at home. When the whole was washed 

 under running water and dried, I picked out from 

 the mass about 200 of the macrospores, some of 

 which I mounted and sent to you. Previously to 

 this I sent some to a friend at Morpeth, and, at his 

 request, some to W. Carruthers, Esq., F.R.S. I 

 have now a few more for distribution, if any one 

 interested in botanical studies desires a slide. 

 Quoting from the letter I received from my friend, 

 he says,—" As the woody nature has been in part 

 preserved in these spores, you might possibly secure 

 some stems that would reveal structure from the 

 same spot." Acting upon this suggestion, I paid, a 



* W. C.Williamson, F.R.S. 



