ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 193 



^ grin., absolute alcohol 100 c.c), then washed in absolute alcohol* 

 passed through xylol and mounted in balsam. Sometimes the prepar- 

 ations were unmounted by dissolving the balsam in xylol and after 

 removing the hematoxylin by means of iron-alum were restained by 

 means of T wort's stain. 



Sections of stomachs of infected fleas were also made. The viscera 

 were fixed in the strong Flemming fluid or in Maier's modification 

 of Schaudinn's fluid. The fixatives were allowed to act for about one 

 hour, and the Flemming's solution was found to give the better results. 

 The fixed stomachs were placed, three at a time, on thin slices of amyloid 

 liver and stuck on with a tiny drop of glycerin-albumin. After fixing 

 the stomachs to the liver in 90 p.c. alcohol, they were imbedded in 

 paraffin. Celloidin imbedding did not give good results. The most 

 suitable thickness for the sections was found to be 6/*. Though 

 numerous methods for staining were tried, only two gave satisfactory 

 results, viz., iron-haematoxylin followed by Lichtgriin -picric in absolute 

 alcohol, and Griemsa's method. 



(5) Mounting-, including- Slides, Preservative Fluids, etc. 



Mounting Diatoms in Oil of Cassia.*— H. Miles-Carter states that 

 this is an excellent, cheap, easily obtained medium, and with it the image 

 obtained is far stronger than with balsam. He proceeds as follows : — 

 Cement to a clean glass slip, a thin glass or tin cell, using isinglass 

 cement or hard paraffin wax. Have ready the cover with the diatoms 

 dried upon it, fill the cell with oil of cassia, slightly warm the cover, 

 and lower it on to the cell, being careful to avoid air-bubbles. Remove 

 with blotting-paper the superfluous oil from* the outside of the cell and 

 cover, taking care not to allow any of it to get on the upper surface of 

 the cover, and, having ready a pot of melted hard wax, run this (with the 

 aid of a hot wire and small brush) into the space between the outer edge 

 of the cover and the slip ; do not allow any air-bubbles to remain, get 

 them out with a hot needle. When the wax is solid, the superfluity can 

 be cleaned off with a penknife to within J in. of the edge of the cover, 

 and the glass cleaned up with a piece of rag. Then run a hot wire 

 round the edge of the wax on the slip, so as to ensure a sound junction 

 with the glass, then trim up as before. Give two coats of thick collodion, 

 and an hour later a good coat of seccotine. Put the slide aside for 

 24 hours, then finish with shellac varnish. 



(6) Miscellaneous. 



Elements of Microscopical Technique and Vegetable Histology. f 

 J. Ocboterena, who is the Director-general of Primary Education of San 

 Luis, Potesi, has compiled a tract dealing with the elements of micro- 

 scopical technique and vegetable histology. It contains 50 pages and 

 17 illustrations. The contents are common to all elementary works on 

 microscopical technique, and the printing of the illustrations is very 

 imperfect. 



* Journ. Micrology, 1914, pp. 95-6. 



t San Luis, Potosi, Mexico, 1914, Pasciculo i. 



