1 84 



HA RD WICKE'S SCIENCE- G OSSIF. 



MICROSCOPY. 



To Advertisers. — The following is a quotation 

 from a long letter just receivetl from a new corre- 

 spondent of SciENCE-Gossir in India : — " It is 

 useless my saying anything in praise of your paper 

 beyond that it was the cause of my purchasing two 

 microscopes, &c., for myself." Verb. sap. 



The Journal of the Royal Microscopical 

 Society for June contains, besides the usual sum- 

 mary of current researches relating to zoology and 

 botany (principally invertebrate and cryptogamic), 

 the following papers: — "New and Foreign Roti- 

 fera," by Surgeon V. Gunsen (illustrated) ; " A New 

 Method of Infiltrating Osseous and Dental Tissues," 

 by T. Charters White ; and " On Bulls' Eyes for the 

 Microscope," by C. M. Nelson (illustrated). 



Mason's Improved Oxyhydrogen Lantern 

 AND Table Microscope.— We have much pleasure, 

 after carefully examining this elaborately got-up, 

 well finished, and yet marvellously compact instru- 

 ment, in stating that it is the best and cheapest yet 

 issued. It affords new scope for lecturing purposes, 

 — botanical, zoological, or geological — the polari- 

 scope bringing out the colours of the lithological 

 slides very clearly and effectively. This in.strument 

 has been designed to meet a long-felt want, i.e., a 

 microscope that can be used to demonstrate to a 

 large audience, or, when not in use that way, easily 

 converted into an ordinary form of table stand. 

 This is done by merely slipping it off its lantern 

 fitting and putting it on to another stand furnished 

 with joint for placing instrument at any angle, having 

 flat and concave mirrors, substage fitting tube of the 

 universal size. One special feature is an improved 

 form of object-holder ; the springs are easily moved, 

 and will hold M'ith equal ease a thick zoophyte 

 trough or the thinnest 3 by i slip ; the objects can 

 be moved about without the fear of scratching the 

 labels, &c., an objection so common in the ordinary 

 spring stages. The object and objective are clearly 

 in View while focussing ; this is of the utmost im- 

 portance in photo-micrography, especially with the 

 higher powers, also when using the camera lucida, 

 the object is held gently but firmly in position, and 

 can be readily manipulated. The optical parts have 

 been specially worked out and give results equalling 

 instruments costing several times its price. The 

 various insect parts are beautifully pictured, sharp 

 and clear to the edges. Living organisms such as 

 hydra, daphnia, or other forms of pond life, are 

 beautifully depicted, and can be shown either to a 

 class or general audience. The instrument can be 

 fitted to any ordinary lantern with 4-inch condensers. 

 There are no screws or loose parts, so that the fear 

 ef losing screws is entirely avoided. All working 

 parts are compensated for wear. 



ZOOLOGY. 



The Colouring and Banding in Land and 

 Fresh-water Shells. — We have received another 

 paper on this subject from Mr. S. Pace, who was 

 away from England when Mr. J. J. Williams answered 

 his criticism. ]Mr. Pace protests against "the free 

 way " in which his article was altered ; but the editor 

 can in no instance allow any other than strictly 

 scientific remarks. Especially will all personal ones 

 be excised. 



New Species of Kangaroo. — The latest dis- 

 covered marsupial is the curious little burrowing 

 kangaroo {Notoryctes typJilops), found in the heart of 

 Australia, on the telegraph line between Adelaide 

 and Port Darwin. The eyes are mere spots beneath 

 the skin, so that it probably lives almost entirely in 

 darkness, and it certainly digs a hole in the sand 

 with amazing rapidity. It is the most mole-like of 

 its order. 



Hydrobia Jenkinsi, E. A. Smith.— Mr. W. 

 Crouch has so completely answered Mr. W. H. 

 Smith's note in the July number of Science-Gossip, 

 that there is very little left to comment upon. It is, 

 however, I think, necessary to point out to Mr. 

 Smith, that supposing his friend was the first dis- 

 coverer of the species, it would not affect its nomen- 

 clature, after Mr. E. A. Smith had so thoroughly 

 established its claim to specific rank, after patient 

 comparison and research. Mr. Smith's note certainly 

 conveys the impression that he has but little acquain- 

 tance with the subject, and he certainly cannot have 

 read the various articles which have appeared in 

 Science-Gossip, and other journals, describing the 

 new species, its first discovery, and habits and 

 distribution, or he could not surely have overlooked 

 the statement that I had collected the species some 

 six years previous to Mr. E. A. Smith's announce- 

 ment that it was a new species. My first specimens 

 were obtained from ditches at East Greenwich 

 marshes, June 19th, 1883 ; a few weeks later they 

 were fairly abundant in that locality. Two or three 

 years after I found a few shells only at Plumstead 

 marshes upon several occasions, but they did not 

 abound at that time according to my own experience. 

 Immediately after obtaining specimens in 1883, I 

 forwarded a number of them to various concholo- 

 gists, asking them to name them for me. They were 

 unanimous in pronouncing them to be Hydrobia 

 similis of Draparnaud. It has of course been con- 

 clusively proved by Mr. E. A. Smith of the British 

 Museum, that they differ nearly as much from this 

 species as from the variety ovata of //. ventrosa. 

 (See Journal of Conchology, vol. vi. p. 142). It is 

 to be regretted that the mistake should have occurred, 

 but no doubt it originated from the scarcity of 



