106 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Two main advantages of this apparatus are that the dilutions pre- 

 pared at the bedside may be transported conveniently in the diluting 

 cells to the laboratory, and may there be examined at leisure. Secondly, 

 the eyepiece grating shows dead black lines on a white ground, and thus 

 less eye-strain is caused by the use of this apparatus. 



The Beginner's Guide to the Microscope, by C. E. Heath.* 

 This little book is one of the useful manuals published by Messrs. 

 Percival, Marshall and Co. Its aim is to be thoroughly practical and 

 helpful, and it admirably succeeds in carrying out its purpose. The 

 author studiously adopts a simple style of language, and writes in a 

 manner intended to popularize the instrument. In addition to sections 

 describing the Microscope itself, there are others devoted to the simpler 

 methods of slide-mounting. 



Weight, F. E.— Microscopical Petrography from the Quantitative View-point. 

 [Gives a valuable survey of the present condition of this branch of science.] 



Journ. Geology, Sept. to Oct., 1912, pp. 481-501. 



B. Tecliiiic[ue.t 

 (1) Collecting- Objects, including- Culture Processes. 



Cultivation of Mosses on Sterilized Media.J — Servettaz records 

 that he has obtained successful cultivations of twelve species of mosses 

 in liquid and solid media. The cultivations were made from spores 

 which were sown directly on the medium, though it was found better 

 to employ a moist substratum, both for convenience of observation or 

 to ensure a better aeration of the cultures. In Erlenmeyer's flasks or 

 in Petri dishes was placed a layer of absorbent cotton-wool, and this 

 was covered with a layer of thick blotting-paper. When test-tubes 

 were used, slips of filter-paper dipped into the medium gave suc- 

 cessful results. 



Plates of porous porcelain were also employed, but the results were 

 not altogether satisfactory. 



The success of the experiments was found to depend principally on 

 careful regulation of temperature and light. The optimum temperature 

 lay between 16°-25°, while the amount of light had to be regulated 

 according to the species, good results being obtained only by constant 

 and careful supervision. 



Cultivation of the Mammalian Blastoderm.§ — A. Brachet set 

 out to investigate whether an egg or a young blastocyst is capable of 

 living and of developing outside the maternal organism, and if so, does 



* Published by Percival, Marshall and Co., London. 



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

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

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

 (6) Miscellaneous. 



X Comptes Rendus, civ. (1912) pp. 1160-2. 



§ Comptes Rendus, civ. (1912) pp. 1191-3. 



