108 SUMMARY OF CURRENT RESEARCHES RELATING TO 



the latter of substances which, on examination by crossed Nicol prisms, 

 are found to be anisotropic. These substances appear as globules, or 

 " myelin figures " ; they are normal in the suprarenal gland, and occur 

 very frequently in pathological tissues, characterising a most important 

 type of fatty degeneration. These substances are composed of fatty 

 acids and cholesterin, neither of which will stain separately ; but if the 

 two are present in a " myelin-like " compound, staining or oxidisation 

 immediately takes place. Several experiments make it almost certain 

 that cholesterin is the substance oxidised. This seems to throw fresh 

 light on the part which cholesterin plays in cell-metabolism. Two other 

 constituents of the medullary sheath, viz. lecithin and protargon, do not 

 seem to be concerned in the results of Weigert's myelin method, which 

 would appear, then, to depend on the existence in the medullary sheath 

 not merely of unsaturated fats, but of such in the form of a compound 

 with cholesterin, which gives "myelin figures" when heated in contact 

 with water. 



(5) Mounting-jiincluding: Slides, Preservative Fluids, etc. 



Mounting Amphibian Eggs.* — K. Ogushi describes a procedure 

 for mounting eggs of Amphibia for demonstration purposes. It con- 

 sists in immersing the eggs in • 5 p.c. formalin, after previous fixation 

 in chrom-acetic acid, Zenker's fluid, or sublimate. In about six months 

 the gelatinous sheath has dissolved away. The next step is to make a 

 very thick ring on a slide with balsam by aid of the turntable. The 

 circular well is then filled up with the prepared roe and closed by means 

 of a cover-shp, previously heated. After pressing down the slip, the 

 margin should be further secured by means of some varnish. The 

 slides should be allowed to rest for some months. 



(6) Miscellaneous. 



Photomicrographic Atlas of Fibres important in Arts and 

 Commerce.! — The first part of this atlas (the sub-title of which is 

 A Manual of Microscopical Research Methods for materials used in 

 textile fabrics, in the manufacture of paper, rope, string, and yarn) has 

 recently appeared. The author is Alois Herzog, one of the principals in 

 the Prussian High School at Sorau, where there is a special textile 

 industry department. The work, which is subsidised by the Prussian 

 Government, represents the results of fifteen years' labour. In the 

 text are described the apparatus required, the necessary technique, the 

 microchemical reactions, and the microscopy of the fibres and of the 

 plants from which they are derived. The atlas contains 222 photo- 

 micrographs, one being in three colours. These are all most excellent, 

 and of course are faithful reproductions of the originals. This atlas will 

 form one of the most valuable works on this particular branch of 

 microscopy, and will be of the greatest assistance to students and 

 learners. 



* Anat. Anzeig., xxxiii. (1908) pp. 381-2. 

 t Munich : J. B. Obernetter, 1908. 



