SCIENCE-GOSSIP. 



229 



however, so well known, that we will not describe it 

 in detail, but content ourselves by stating some of 

 its special points. It first strikes one in appearance 

 as more like an engineering tool than a scientific 

 instrument, it has a heavy cast-iron frame and lacks 

 the flimsy and brilliant appearance so characteristic 

 of many scientific instruments. The essential parts 

 are carefully made, but the rest is left rough and 

 painted. It is clear that in designing this instru- 

 ment, an appreciation of the importance of extreme 

 stiffness was necessary, and hence the heaviness 

 of the base. The "five point" or kynematic 

 principle has also been largely used ; that is, the 

 moving parts are each supported by the requisite 

 number of points to give the required freedom of 

 motion and no more. This prevents any bending of 

 the pieces, and ensures the absolute identity of two 

 consecutive movements. This latter point is all 

 important when we are dealing with such small 

 quantities as the difference of the thickness of 

 sections. The arrangement also for advancing the 

 object the required amount after the section is 

 cut, is new and works extremely well. The new 

 pattern rocking microtome, of the same company, 

 has many of the features of the original, but with 

 one fundamental difference, the sections are 

 perfectly flat. The sections in the original instru- 



ment are parts of .a cylinder of radius ninety 

 millimetres, and no doubt that with larger objects, 

 such as can be cut with the new instrument, such a 

 curvature would be a disadvantage. It is easy, 

 however, to make too much of this point. If we 

 have an object five millimetres wide in the old 

 rocking microtome the extreme edge of the section 

 will be 034 millimetres distant from the flat surface. 

 It is clear that it would be difficult not to distort 

 any soft substance far more than this in mounting 

 it in the paraffin block, and hence the error caused 

 by the old microtome not cutting a truly plane 

 section must be of little or no importance in most 

 cases. Sections as large as thirty millimetres in 

 diameter can be cut with the new instrument, and 

 an object twelve millimetres long "can be cut 

 throughout its whole length without readjustment. 

 The thickness of the sections can be read off a 

 graduated arc at once, which, no doubt, is a great 

 convenience. The object can be clamped clear of 

 the razor, in which position it can be easily manipu- 

 lated. The razor also can be clamped either at 

 right angles to the direction of motion or else 

 diagonally, so as to give a slicing cut, also by 

 adjusting two screws the razor can be tilted so as 

 to increase or diminish the amount of clearance 

 between its back and the object. 



THE NEW LEPIDOPTEROLOGY. 



TV/TR. EDWARD MEYRICK has raised a 

 standard of revolution in the land, and we 

 have no doubt that there will be a considerable 

 rallying of supporters. In fact, in general principle 

 we should be among them, though after careful 

 perusal of his new book (" A Handbook of British 

 Lepidoptera," by Edward Meyrick, B.A., F.Z.S., 

 F.E.S., Assistant Master at Marlborough College, 

 847 pp. large 8vo, illustrated. London and New 

 York: Macmillan and Co., 1895. Price 10s. 6d.) 

 we have come to the conclusion that the author 

 will in a few years, as he extends his investigations, 

 modify some of his conclusions with regard to 

 certain British species. 



Mr. Meyrick has produced the most advanced 

 book which has been written during the present 

 half century upon the British Lepidoptera ; and 

 though it will severely shock adherents to the old 

 school to find the arrangement of our species 

 commencing with Caradrinina, — the first in the list 

 being Oeonistis quadra, with the butterflies wedged 

 in in the middle of the book between Gastropacha 

 quercifolia and the Pyrales, we consider that he 

 is upon the right road towards scientific grouping 

 of our moths and butterflies. From the preface we 

 learn that the system of classification adopted by 

 the author, though now fully published for the 



first time, is not based on the British species only, 

 but is the outcome of his study of the Lepidoptera 

 of the whole world. 



The table of genera in his group Caradrinina 

 includes Sarrothripus, Halias, Hylophila, Lithosia, 

 Oeonistis, Earias, Roeselia, Nola, Coscinia, Nudaria, 

 Arctia, Uraba, Diacrisia, Phragmatobia, Tyria, 

 Gnophria, Cybosia, Setina, Miltochrista, Callimorpha, 

 Utetheisa and others, including the genus Plusia. 

 Following Caradrinina comes Notodontina with a 

 number of genera which are now arranged among 

 the Geometers, as well as Saturniadae, Sphingidae 

 and others. Third is the group Lasiocampina, then 

 follows Papilionina, which contains the butterflies, 

 commencing with the Nymphalidas, Anosia crippus 

 (= plexippus) taking first place; Argynnis is next, 

 followed by Melitaea and Vanessa. The genus 

 Lyccena is divided with Chrysophanus, which 

 includes argiades, minimus, semiargus, astrarche,phhieas 

 and dispav. The remainder of the blues are under 

 the generic name Lyccena. These are followed by 

 Colias, Goneptcryx, EucJiloc, Leucophasia, Pieris and 

 Aporia. Then follows Papil to machaon. The next are 

 the Hesperiadae, at the end of which we find 

 Pamphila. Group number five is Pyralidina; number 

 six is Psychina, a curious group, for it includes the 

 genus Psyche, Ztuzera pyrina (asculi), Phragmatcecia 



