SC7/£IVCE-G0SS/r. 



87 



KoRAMiNlKKRA KROM KENT.— With ihe approach 

 ol the holiday season some of our readers who are 

 thinkinj; of visitinji Margate may he j;rateriil to Mr. 

 Frank I'. .Smith for reminding them that the smooth 

 sand siirroiindint; the extremity of the Nayland Ki>ck 

 breakwater is a yood locality lor collectinj; foraniini- 

 fera. Mr. liarland's articles in the two last numbers 

 of SilKM:|.:(;i)s.sif («///,- pp. 8 and 53), jjive most 

 complete and detailed methods with regard to the 

 treatment of ttiis material. 



Ul.\MoMi Bi;iyi IKS. -Mr. Smith also recommend.s 

 Epping Korest as a good locality for the heautiful 

 diamond beetles found in every cabinet of microscopic 

 objects. They may be picked from the trunks of trees, 

 or collected by simply sweeping a net amongst the 

 nettles and low herbage. .Mr. Smith recommends 

 that the beetles should be dried for some weeks before 

 mounting whole, and suggests that a cyanide bottle 

 only should be used for a killer, as spirit has a tendency 

 to destroy the colour. 



I'ARASITKS OI- IIOUSK F'l.IKS AND BlRDS. — Mr. 

 Cran also sends drawings of a red parasite, taken 

 from a house tly, and of another parasite taketi from a 

 bird. I le found two of the former concealed under 



P.VRv^SITK OF Hol'SE Fl-V. 



Fig. I vcntr.ll aspect X ,80. Fi(i. 2 a foot of 3rd pair X jto. 



Fip. 3 mouth organs X 260. 



the antennae. He adds that he has found parasites 

 with similar mouth-organs on grasshoppers. The 

 latter were found on the larger feathers of the birds' 



Parasitk ot* Bmns. 

 Fij;. I male. Fig. j female x 60. Fig. 3 foot of female X a6o. 



wings, and were grayish in colour. Like the " Bete 

 rouge " these parasites come from Antigua, West 

 Indies. Mr. Cran would be glad of any information 

 with regard to any of them. 



MICKOSCOI'N KjU BKGINXKKS. 



Etv F. SlIIULINUTOM SCALK.S. F.K..M.S. 

 (VanI ill ititl from f>a^f ,^t>.) 



\Vk now come to Ihe sub.stage condenser, a piece 

 of apparatus that originated in Kngland. Without 

 this no microscope stand can be considered complete, 

 or capable of doing good work with any other than 

 low powers. It is the adjunct that make.s' the modern 

 microscope so enormously superior to its prcdece.s,sors, 

 and is second only in importance to the invention of 

 the achromatic objective. Its otl'ice is to gather 

 together, concentrate and focus the light upon the 

 object. No microscope should be purchased that has. 

 not fittings for such a conden.ser, or to which the con- 

 denser cannot at any rale be subsequenlh- readily 

 added. In its simplest form it is merely a ring fitted 

 beneath the stage and accurately centered with the 

 optic axis of the microscope. The inside diameter of 

 this ring should be Ihe " Society '" size, i.e., \\ inches, 

 full. As, however, the centering of the objectives 

 themselves generally varies more or less, it is a greal 

 advantage to have some means of slightlv altering the 

 centering of this ring. Further, as the condenser 

 re(|uires focussing like the objective, a focu.ssing 

 adjustment becomes more than a convenience. This 

 may be by rack and pinion, or by one of the cheaper 

 forms of adjustment made by certain makers for their 

 less expensive stands. Failing this, the condenser i.s. 

 made to slide in the fitting or ring, in its simple form, 

 to which I have above alluded. 



We have now briefly enumerated the essentials of 

 a modern microscope stand, and it will be advisable 

 here to illustrate certain typical stands of individual 

 makers. We have purposely selected for illustratioiv 

 microscopes by makers who are in the front rank, and 

 whose riames are a guarantee of good workmanship, 

 .and desigti. We have, of course, relied opon our own 

 judgment in making such selection, but we wish it to 

 be clearly understood that we make no invidious 

 distinctions, that there are other stands and also other 

 makers, which our space and the scope of our 

 articles alone prevent us from enumerating in detail. 



Messrs. K. and J. Beck, of Cornhill, have recently 

 brought out a greatly improved model of thci'r 

 former "Star" microscope which thev call the 

 •' British Student's." With rack and piiiion coarse 



R. & J. Beck's British Stide.vt's Microscope. 



adjustment, micrometer screw fine adjustment, draw- 

 lube engraved with millimetre scale, double mirrors, 

 under stage fitting with iris (/.t-., contracting) 

 diaphragm, and large tripod stand, this microscope 



