492 



KNOWLEDGE & SCIENTIFIC NEWS. 



[July, igo6. 



Conducted by F. Shillington Scales, b.a., f.r.m.s. 



R-oyal Microscopical Society. 



May 16, Dr. Dukinfield H. Scott, I'rc-sitk-nt, in the 

 I'liair. Dr. Htrnstein ga\c an account of some ob.ser\'a- 

 tions recently made on the para.sites of malaria, and 

 the phagocytic action of the polymorphanuckar 

 leucocytes. Tlie subject was illustrated by a large num- 

 ber of drawings on the blackboard, showing the result 

 of e.\aminations made at intervals of a few minutes 

 during a period of five hours, upon the blood of a 

 patient suffering from malarial fever. A crescent form 

 of the parasite was seen to become engulfed by a 

 leucocyte, in which it was .soon surrounded by vacuoles 

 and ultimately destroyed, only the pigment granules 

 remaining, w^hich were themselves afterwards ap- 

 proached, and absorbed by other leucocytes. The 

 blood film was stained, and the preparation, showing 

 the pigment granules in the polymorphonuclear 

 leucocytes was exhibited under a microscope at the 

 meeting. Mr. C. Beck exhibited and described a sim- 

 ple wave-length spectrometer, for the purpose of test- 

 ing colour screens, designed by Mr. E. M. Nelson, in 

 conjunction with Kir. J. W. Gordon. It consisted of a 

 diffraction grating, a slit, a collimating lens, and an 

 eye lens. Mr. (Gordon had worked out a method of 

 measuring wave-lengths by this instrument without 

 any reference tO' tables, as shown by a diagram ex- 

 hibited, the wave-lengths being read off in millionths 

 of an inch. The President then referred to the annual 

 exhibition of pond life, in giving which, the Fellows 

 had been greatly assisted by Members of the Ouekett 

 Microscopical Club. Nearly 40 microscopes were upon 

 the tables. 



Quekett Microscopical Club. 



On May 18, Mr. A. E. Smith gave an account of the 

 three methods he employed in stereo-photomicrography. 

 In the first described, an arrangement similar to a 

 VVaterhou.se diaphragm, in a photographic lens, is fitted 

 above theobjective, the aperture being eccentric to the 

 opticrj axis of the microscope. Photographs are taken 

 first with the aperture on one side of the axis, and 

 then with the aperture on the opposite side of the 

 axis. In the second method, which is very effective, 

 the object is tilted up on the right and on the left 

 respectively, for the two photographs. The third 

 method was to first photograph the object in the usual 

 way, and then to shift it laterally, very slightly, of 

 course, before taking the .second photograph. A num- 

 ber of excellent stereograms obtained as above 

 described were exhibited. 



Mr. D. J. Scourfield, l>M\.M.S., ga\e an account of 

 " Mendel's Law, and its Relation to Microscopy." 

 Mendel's work was done in i86q, but was lost sight 

 of until I goo. Details of some of his experiments were 

 given, and his success in framing a law of heredity 

 was attributed to his method of fixing his attention upon 

 pairs of characters without trouliling about the hybrid 

 as a whole. Mendel's law stated shortly, is that, when 



the germ-cells of hybrids are formed, half of them 

 contain the factor for one of each pair of characters, 

 and the other half the factor for the other character. 

 This generalisation accounts not only for the fact.s 

 bro'Ught forward by Mendel, but also for a very large 

 range of additional ca.ses recently investigated. After 

 dealing with the relation of Mendelism to micro.scopy, 

 and the pcxssible utilisation of microscopic organisms, 

 such as the Entomostraca, for experimental work, at- 

 tention was directed to the necessity for the modifica- 

 tion of certain current views on " pure " races, varia- 

 tion, and the origin of species, which follow the ac- 

 ct-ptanre of .Mendel's law. 



Quekett Club Journal. 



The half-\earl\-, April issue of the Journal of the 

 Quekett Club contains several interesting papers 

 which have been read before the Club, and briefly re- 

 ported in " Knowledge." Amongst these is an 

 account of Mr. E. J. Spitta's experiments on the com- 

 pound eyes of insects, which lead him to suggest that 

 the facets of the cornea are in reality nothing but 

 minute holes, filled, possibly, with some non-refrac- 

 ti\e material, and forming in the eye what is known 

 as "pinhole images," which may consequently be 

 well defined. The Journal also contains Mr. Spitta's 

 Presidential Address on " The Relative Merits of the 

 Long and Short Tube Microscopes," which, with the 

 .t^ubsuqucnt discussion, is, however, somewhat incon- 

 clusive; full particulars of Mr. Dollman's and Mr. 

 Taverncr's respective methods of making stereo-photo 

 micrographs, with some excellent plates illustrating 

 results; and other papers. The notices of new books 

 again find a pl.ice in the Journal. 



Injection for Fine Vessels. 



P. Konascko successfully and easily injects the organs 

 of small animals by the follow ing procedure : When 

 it is desired to inject, say, the portal system of the 

 kidney of the frog, a canula is introduced into the vena 

 cava inferior or the vena abdominalis anterior. These 

 large vessels are then injected with warm, colourless 

 gelatine. The organ is, of course, placed in a water 

 bath during the injection. When the operation is com- 

 pleted, the preparation is removed and allowed to cool. 

 It is now easy to insert a canula into the finer vessels, 

 which are distended by the injection-mass. When the 

 canula is fastened, the preparation is placed in warm 

 water again. After an immersion of a few minutes, 

 the gelatine is liquified, and then the injection-mass is 

 easily syringed in. 



Flagella of Tubercle Bacillus. 



!\Ir. E. M. Nelson, who is well-known as one of our 

 most experienced and careful micrcscopists, and who 

 first demonstrated the beaded, or, as he now calls it, 

 jointed, appearances of the stained tubercle bacillus 

 in the same year as its discovery by Dr. Koch, namely, 

 in 1882, has recently stated that he has observed this 

 bacillus to be flagellated. In view of the generally ac- 

 cepted opinion that this bacillus is non-motile, con- 

 firmatory evidence of this observation is necessary, but 

 Mr. Nelson's skill and experience, and above all, his 

 caution, make the statement one that must be received 

 with respect. Mr. Nelson states that he has observed 

 bacilli with single flagella, and others, with a flagellum 

 \isible at each end. He gives the uncorrected length of 

 the bacillus as 2.-g\p- long, and '34^ broad, and the 

 length of the flagellum as i-24m. 



