372 SUMMARY OF CURKENT RESEARCHES RELATING TO 



burg on the myelins, myelin bodies, and potential fluid crystals. After 

 noticing- the physical and chemical characters of myelin, they enumerate 

 the conditions under which myelin bodies may be found, and then point 

 out that ofttimes they possess the property of double refraction. From 

 this and other considerations the doubly refractive globules must be 

 regarded as fluid spiiero-crystals. 



Investigation showed that a large number of substances of the 

 nature of soaps gave this particular reaction; that the only crystalline 

 fluids known which are in the intermediate state at the room tem- 

 perature are certain of the oleic acid compounds ; that fatty acid is an 

 essential constituent of myelin, and that of the fatty acids oleic acid 

 plays the most important part. 



Quekett Microscopical Club. — The 4o8th Ordinary Meeting of the 

 Club was held at 2U, Hanover Square, the President, Dr. E. J. Spitta, 

 F.R.A.S., F.R.M.S., etc., in the chair. A paper by Mr. James Murray, 

 on " The Tardigrada," was read by Mr. D. J. Scourfield. The author 

 gave a general account of the history of this group from the first 

 mention in 177;-') down to Richter's work of 1900. A general descrip- 

 tion of the group followed, and the paper concluded with some 

 suggestions and hints on the collection of specimens. Mr. B. J. 

 Scourfield, F.Z.S., F.R.M.S., read a paper on " An AJona and a Pleuroxus 

 new to Britain." The first was Alona tceUneri Keithack, closely allied 

 to A. costata, and the second, Phuroxus denticulatus Birge, a typically 

 American species, but taken by Mr. Scourfield at Exminster, Devonshire, 

 in August, l'.)05. 



At the 4;VJth (3rdinary Meeting, held on April 19th, Mr. G. G. Karop, 

 M.R.C.S., F.R.M.S., Vice-President, in the chair, Mr. D. J. Scourfield, 

 after some introductory remarks on the group, read a paper communicated 

 by Dr. Eugene Penard, of (reneva, on" The Collection and Preservation 

 of Fresh-water Rhizopods." 



GuYEB, M. F. — Animal Micrology : Practical Exercises in Microscopical Methods. 

 Chicago, University Press ; and London, T. Fisher Unwin : 



(190G) ix. and 240 pp. 



B. Technique.* 

 (1) Collecting: Objects, including Culture Processes. 



Thermostat for Low Temperatures.f — W. Kiintze has devised the 

 following apparatus : A double- walled wooden box, 1 • 10 ra. long, • f^5 m. 

 deep, and 0'9o m. high, lined with zinc, and provided, with wooden 

 and glass doors, the space between the walls being ?> cm. ; situated 

 above and below are water tanks for cooling and warming respec- 

 tively. The temperature of the warm tank is regulated by a gas 

 regulator, whilst the temperature of the upper tank is regulated by 

 the inflow of cold water from a water supply which is stopped or in- 

 creased automatically by the action of an ether vapour regulator (fig. 64). 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, etc. ; 

 (6) Miscellaneous. t Centralbl. Bakt., 2te Abt., xvii. (1906) p. 684. 



