26 



KNOWLEDGE. 



January. 1915. 



Mr. Scourfield pointed out that in tropical forests ponds 

 and water on the ground are rarely met w'ith, and it was 

 difficult to locate the breeding places of mosquitoes until 

 it was found to be in water held in the Uttle cups on the 

 tree trunks and roots. 



^^'hen he first commenced to search for Entomostraca 

 in these situations Ids curiosity was rewarded by finding 

 the remarkable bUnd Copepod [Belisarius viguieri), which 

 had not pre\'iously been found in this country. He was now 

 able to report that on several occasions he had found a new 

 Copepod in such little reservoirs of water on trees in Epping 

 Forest, and up to the present they have been found nowhere 

 else. 



The new species evidently belongs to the Harpacticid 

 genus Moraria, described by T. and A. Scott, and so named 

 because first found in Loch Morar, Scotland. Eight 

 species are known, three of which have been found in the 

 British Isles. He stated that he proposed to call it Moraria 

 arboricola, because of its tree-dwelling habit. It is a very 

 small form, the female measuring only about one-fortieth 

 of an inch in length, of the type of Cyclops, Canthocamptns, 

 and Diaptomus. 



The genus is peculiarly adapted to exist in but little 

 water, and when placed in this element could not swim at 

 all well, but -wriggled about rather than swam. 



In Mr. Scourfield's experience, the specimens are mostly 

 found in the earljr part of the j'ear. 



Rephnng to questions he stated that he could give no 

 information as to how they spread from place to place ; 

 that it must be supposed that they resisted the effects 

 of evaporation, as do similar creatures whose eggs and 

 adult forms dry, and become embedded, and remain for long 

 periods in a condition of suspended animation. He also 

 pointed out that one species of Cyclops and one of Cantho- 

 canihlus form a land of cocoon. He commented upon 

 their wonderful vitality. In one case specimens left in 

 a bottle were kept ahve for four years by simply renewing 

 the water from time to time to make up for evaporation. 



The five hundred and third ordinary' meeting of the 

 Quekett Microscopical Club was held at 20, Hanover Square, 

 W., on Tuesday, December 22nd, Professor E. A. Minchin, 

 M.A., F.R.S., Vice-President, in the chair. 



Mr. J. Grundy, F.R.M.S., read a communication from 

 Mr. E. ;M. Nelson of interest to metallurgists. A slide was 

 exhibited, consisting of a thin aluminium disc of about 

 one millimetre in diameter, mounted by itself, ^\^len 

 placed under a j- or J-inch objective, and illuminated by 

 one of the universal condensers, lamp, and bull's-eye, a 

 strong top-illumination is obtained by reflex light from 

 the front lens. Mr. Nelson points out that the idea is not 

 new, having been expounded by Rainey sixty years ago ; 

 later by Professor B. T. Lowne ; and again, more recently, 

 by Mr. J. W. Gordon at the Royal Microscopical Club. 

 He suggests that if, instead of using a cubic half-inch of 

 metal, a piece of wire, say, 1 -5 millimetres thick, were polished 

 and stuck on a slip, it could be investigated quite as well. 



Mr. |. Wilson, F.R.M.S., read some notes by !Mr. H. 

 Whitehead, B.Sc, on an epizoic infusorian {Tridtodina 

 steinii C. and L.) found on Turbellaria. Examples were 

 discovered on a specimen of Mesostoma teirjgonu>n moving 

 about the body and between the folds, closely allied to 

 T. pediciUn.-, differing only in that the latter has an inner 

 as well as an outer ring of teeth. The body varies consider- 

 ably in shape ; when at rest it is cylindrical (sloping), 

 with the base diameter equal to height, about 40;u. The 

 basal circle of cilia is in contact with the host ; the adoral 

 cilia form a spiral leading to the mouth, ^^^len free- 

 swimming, the adoral cilia are retracted, and the basal 

 cilia used for locomotion. The protoplasm contains a 

 number of spherules and one or two contractile vacuoles. 

 The nucleus is large and horse-shoe-shaped, and only seen 

 when stained. 



Mr. Wliitehead pointed out a discrepancy in Saville 

 Kent's description, probably taken from Clapar^de and 

 Lachmann, who stated that the posterior horn^^ ring was 

 continuous and denticulate only on its outer edge, whereas 



it consists of an outer circle of cilia, and within this a circle 

 of from eighteen to twents' chitinous teeth, with points 

 directed outwards. 



Vejdorsky confirmed this pointin 1881, and stated thathe 

 had found T. sieinii on Planaria gonocephala. There is no 

 evidence of parasitism or inconvenience to the host ; 

 therefore the non-committal term " epizoic." 



Mr. J. Burton read a paper by Mr. E. Jil. Nelson on 

 " Palaeozoic Fungi," the chief object being to draw attention 

 to a comparativelv new and interesting field for micro- 

 scopists. Owing to real fossils from a microscopic point 

 of view only having been discovered during the last twenty 

 years or so, real fossils meaning those in which the cell- 

 structure has resisted the disintegration of carbonisation, 

 there is ample scope for more workers in this branch. It 

 was a most interesting paper, but space prevents more than 

 one illustration of its treatment of palaeobotany. In Mr. 

 Nelson's possession is a slide containing a section of a small 

 seed with the pollen grains in the pollen chamber, just 

 previous to fertilisation, although fifty million years must 

 have passed since they entered. The tracheides and the 

 bordered pits in the cells are also well preser\-ed. He 

 recommends those wishing to take up this subject to read 

 Dr. D. H, Scott's book, " Studies in Fossil Botany " {two 

 volumes ; Black). 



Mr. Burton referred to a slide, exhibited before the 

 members, of a section of the leaf of Epidodendron harcouriii, 

 upon which was observed a brown oval ball. A power of 

 200 showed that it was in part formed by little 

 rods, somewhat interlaced, not unhke the house of the Caddis 

 Worm. They are found singlv, but more often in groups, 

 particularly where the leaf's cell tissue has disintegrated. 

 As no mycelium has been observed, it is not possible to 

 state if the invasion of the leaf took place before or after 

 it had fallen. Mr. Nelson considers it to be a sort of fungus 

 spores (gonidia), a conclusion not considered satisfactory 

 by certain of the members. 



Mr. G. K. Dunstall, F.R.M.S., showed a live specimen of 

 the Rotifer (Callidina hilfingeri), which has only twice 

 previously been seen in England. F. E. R. 



THE LIINIITS OF MICROSCOPICAL MAGNIFI- 

 CATION. — At the meeting of the Royal Microscopical 

 Society, held on December 16th, Mr. J. E. Barnard read 

 a most important paper on " X-Rays in Relation to the 

 Microscope." It is certain that the sciagraphs, principally 

 of foraminifera, exhibited as illustrations, were very much 

 more successful than any others of minute objects which 

 have prexdously been produced. They have, moreover, 

 a very considerable value, insomuch as the internal arrange- 

 ments of the chambers of the shells can be determined by 

 their aid without making a section of the shell, and so 

 sacrificing what might be a unique specimen. Mr. Barnard 

 has kindlv lent us the negatives from which Figures 22-24 

 were made. 



The point of the paper, however, which gives it its claim to 

 the title " epoch-making," applied to it by the Chairman 

 (Mr. Edward Heron-Allen), is the possibilitj", emphasised 

 by Mr. Barnard, of securing magnifications immensely 

 greater than are now obtained by means of the ordinary 

 microscope. 



The wa\-e-length of ;!r-rays is some thousand times shorter 

 than those of light, and if, as I\Ir. Barnard's researches 

 suggest, those rays can be made to take the place of light, 

 we should be able to get a magnification many thousand 

 times as great as we do now. Mr. Barnard showed that 

 A'-rays can be refracted, as have also Messrs. Rankin and 

 Chambers in the columns of " Knowledge " (Volume 

 XXXVII, page 260) ; but it is rather with other in\isible 

 ways of greater wave-length, but still very much shorter 

 than those of light, that it is suggested that practical results 

 are most likely at first to be obtained. The investigations 

 which will have to be made will be long, no doubt, and costly; 

 but Mr. Barnard, who has by his suggestive paper thrown 

 out ideas of which other workers may take advantage, is 

 very confident of ultimate success. 



