i^OS 



HARJ) WICKE'S SCI ENCE-GOSSIP. 



paratiou and Mouiitiiig of Mici'oscopic Oltjects,'" by 

 T. Davics. Published by R. Hardwicke, 192, 

 Piccadilly : price 2s. Gd.) In mounting the fora- 

 niinifera in balsam, great care is required to com- 

 pletely expel the air from the specimens. This may 

 be done by" boiling in a test-tube, with Canada 

 balsam or turpentine, or by the use of the air-pump. 

 After the air has been thoroughly expelled, the 

 specimens must be mounted in pure balsam. It is 

 almost needless for me to say that the specimens 

 must be qidte dry before any attempt is made to 

 expel the air or to mount. If this is not attended 

 to, the objects, if mounted in balsam, will be quite 

 useless ; while, if they are mounted dry, moisture 

 will condense upon the inner surface of the glass 

 cover, and this will prevent a good view of the 

 object. To examine the structure it is necessary to 

 cut sections. This is fully explained in the book 

 before mentioned. When more than one specimen 

 of a species is met with, they should be placed on 

 the slide in different positions. T. Rymer Jones 

 says : " They should be attached to the point of a 

 line needle, so that they may be turned in any 

 direction, and examined by reflected light condensed 

 npon them by means of a lens or side-rcHector." — 

 Wm. Sargant, jiin. 



The Markings on the Test Poduka Scale.— 

 The July number of the Lens contains a paper by 

 Dr. J. U. S. Arnold on the Podura markings. The 

 following is a brief summary of his views on their 

 character : — "There are, I believe, some species of 

 podura that arc scaleless, and are clothed with 

 hairs — compound hairs ; that is, the hairs are 

 covered by projections, usually in considerable 

 number at one end, where they form a brush-like 

 arrangement. It is, then, my purpose to try and 

 establish some points of similarity of structure 

 between the hairs and scales themselves. If we 

 agree that these compound hairs are covered by 

 epithelial scales, as are the hairs of other animals, 

 why should not the scales also be covered with like 

 structures ? There is no doubt that the epithelial 

 scales on the hairs of L. c.nrvicoUis and Degeeria 

 domcdica bear a great similarity to the markings on 

 the scales themselves. They are of the same shape, 

 and I have in several instances made measurements 

 which show the coincidence in size between the 

 'spines' on the hairs and those on the scales. 



If the spines separated from the hair are 



examined by unilateral (oblique) light, a beading 

 may be seen on them, as well as on the spines from 

 the scales. Having satisfied myself as to that fact, 

 the next thing was to separate the spines from the 

 scales. On a slide of B. chmestica, mounted, I 

 believe, by J. Beck, of London, I perceived, to my 

 great satisfaction, a fractured scale which showed 

 the spines projecting beyond the broken edge, some 

 of them bent and distorted." In order to be per- 



fectly sure of the identity of the hair and scaie 

 spines, the M'riter adopted the following methods 

 for obtaining the scale spines separate from the 

 scale : — " I selected specimens of the scales that 

 were not mixed with hairs and that show no free 

 spines, and placed them in such a manner that the 

 discharge from aLeyden jar could be brought to bear 

 upon them, which not only tore to pieces the scales, 

 but scattered the spines far and wide. I also, by 

 means of crushing in an agate mortar, aud even by 

 crushing on the slide by pushing about the covering 

 glass with the handle of a dissectiug-needle, have 

 fractured the scale in such a manner that the spines 

 lay free, and side by side with the broken scale. 

 What more is wanting to show that hairs and scales 

 are of a similar structure ? the hair consisting of a 

 shaft, upon the surface or exterior of which are 

 attached spine-like epithelial cells ; the scale of a 

 flattened shaft, so to speak, covered by analogous 

 structures." The paper is accompanied by an 

 " Albertype " of the fractured scale and detached 

 hairs. The original photograph was taken with a 

 Wales o'o immersion. (I have observed a similar 

 effect on a 'slide of D. domestlca.) The scale is, 

 however, not broken, but partially doubled over in 

 a diagonal direction. Beck's new immersion (/o) 

 shows the so-called beading on the spines very 

 distinctly. The beading forcibly reminds one of the 

 medullary substance, or pith, seen in various hairs, 

 such as the squirrel, mouse, &c. May not this 

 beading or varicosity be caused by an internal 

 pith ? — F. Kitton. 



ZOOLOGY. 



Bavages of Anobium,— Under this head Mr. 

 E. C. Bye has a paragraph in the Entomologist's 

 Magazine for August. He describes that Anobium 

 striatum completely riddles the paper of a pub- 

 lisher, five quires deep, outer wrapper and all. He 

 thinks that a good soaking with boiling water and 

 carbolic acid may suppress its ravages. He states 

 that he has known J. tessellatum actually to bore 

 through leaden rooting. 



Coluber Austriacus.— I am pleased, but not 

 surprised, at heariug that Coluber Austriacus, alias 

 Coronella lavis, has been found in Dorsetshire, I 

 wish your correspondent would be kind enough 

 to say where it was seen. I presume on the 

 Poole and Bournemouth lieaths, where I have long 

 expected it would be seen, in company with the 

 beautiful lizard Lacerta hispimn. This latter has 

 not crossed the chalk downs into the North Hants, 

 or Bagshot moors, as the Coronella has done, pro- 

 bably at a period when the plastic clays (and 

 Bagshot sands over them ?) had not been all but 

 dcinidcd cf the chalk between Winchester and 



