7 o 



KNOWLEDGE & SCIENTIFIC NEWS. 



[March, 1907. 



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



Royal Microscopical Society. 



January v 



1905 



-Annua! meeting. Dr. Dukinfield 



II. Scott, F.R.S., President, in the chair. Mr. Rousselet 

 exhibited under microscopes a collection of mounted 

 -.p., [mens oi Fresh-water polyzoai which included nearly 



all the known species, several being very rare, and 

 others not yet found in this country- Among the 

 specimens were Arachnidia Ray-Lankatcr, from Lake 

 Tanganyika. Statoblasts of Lophopodella Thomasi, from 

 Rhodesia, Pectinatella gelatinosa, from Japan, and from 

 Havel, near Berlin, and Victorella favida. Some ex- 

 cellent stereo-micrographs, sent over by Mr. Dollman, 

 of Adelaide, were exhibited by the Secretary. The 

 Annual Report and Balance-Sheet were read and 

 adopted. The Following officers were elected for the en- 

 suing year : —President, The Right Hon. Lord Avebury; 

 Vice-Presidents, Conrad Beck, A. N. Disney. Dr. J. W. 

 II. Eyre, and Dr. D. H. Scott; Treasurer, Wynne 

 E. Baxter; Secretaries, Rev. Dr. W. H. Dallinger and 

 Dr. R. G. Hebb; Librarian, P. E. Radley; Curator, 

 C. F. Rousselet. The President delivered his annual 

 address, the subject being " The Flowering Plants of 

 the Mesozoic Age in the Light of Recent Discoveries." 

 The address, which was illustrated by about 50 lantern 

 slides, was the last of a series on recent discoveries in 

 fossil botany. 



Quekett Microscopical Club. 

 January 18.— Mr. F. B. Rosseter, F.R.M.S., com- 

 municated a paper, which was taken as read, on two 

 avian tapeworms. Hymenolepis nitida and H. nitidulans. 

 Mr. A. E. Hilton read a paper "On the Nature of 

 Living Organisms." He thought that a complete 

 answer to the question as to what a living organism 

 really was would not be possible for a long time to 

 come. Science tells us that a living organism is an 

 " automatic chemical machine." That all living things 

 have a similar foundation has been well known for the 

 last forty years. This foundation, a substance at first 

 called protoplasm, but now more correctly known as 

 plasm, is defined as colourless, and of a jelly-like con- 

 sistency, about one-half water by volume or weight. 

 In its entirety, it is a colloid, is elastic and highly 

 mobile, but at the same time is tenacious, and not easily 

 diffusable, is not soluble in an excess of water, but 

 without a proper proportion of water in its composition 

 the free action of its vital machinery is impossible- 

 The idea that the honeycomb, granular, or thread-like 

 structures observed are really the characteristics of 

 pure plasm is no longer tenable. The appearances may 

 lie those of plasm products. The subject was then 

 dealt with at considerable length from the "new 

 chemistry " point of view, and stress was particularly 

 laid on the strongly catalytic property c f plasm. 

 rhe lecturei concluded with a review of the known 

 qualities and properties of the " automatic chemical 

 machinery." and considerable discussion followed. 



The Markings of Butterfly Scales. 



The Podura Scale (Lepidoeyrtis curvicollis) has long 

 been a favourite test with microscopists for- moderately 



high-power lenses, such as a quarter or a sixth of an 

 inch, and much time has been spent in resolving the 

 markings into "exclamation marks" (if the utmost 

 tenuity, and with a white inner "exclamation mark " in 

 each dark mark. As a matter of fact, the test is by 

 no means a reliable one, as the 'resolution " is largely 

 a matter of careful adjustment of both light and dia- 

 phragm; but the slide is found in most microscopists' 

 cabinets, and there has been a good deal of discussion 

 as to the exact nature of the markings referred to. 



Grease 



Dr. Alfred C. Stokes, of New Jersey, U.S.A., con- 

 tributes to the December issue of the Royal Micro- 

 scopical Society's Journal an interesting note on the 

 markings of the wing scales of a certain butterfly, 

 remarking that in 1895, Mr. Alfred Letherby, F.R.M.S., 

 published a paper in the Journal, entitled " Notes on the 

 Podura Scale," in which he stated that " this scale is 

 formed of two membranes, one a delicate hyaline mem- 

 brane, from which the stalk extends, and one a denser 

 (optically) brownish membrane, superimposed upon the 

 other. The latter is perforated all over, in the form 

 known as 'exclamation marks,'" and that he presented 

 photographs to substantiate his contention. From 

 what Dr. Stokes has himself observed on the scales of 

 another insect, he judges Mr. Letherby 's statement to 

 be correct. Dr. Stokes had in his collection a slide of 

 the wing-scales of an unknown butterfly, which on ex- 

 amination were shown to be formed of three mem- 

 branes, of which the upper and the lower bear longitu- 

 dinal ribs, between which both membranes are 

 distinctly, even conspicuously, perforated by minute 

 apertures, arranged in rows more or less horizontal. 

 Some of the scales in the preparation had the two mar- 

 gins accidently turned upward, so that both membranes 



