314 SUMMARY OF CURRENT RESEARCHES RELATING TO 



agar method may also be combined with the usual paraffin process. 

 He gives further "details as to staining, clearing, and the like, but the 

 point of importance is the successful results of this agar imbedding for 

 the purpose of minute morphological study of fine elements like blood- 

 corpuscles. 



Methods of studying typical Bird's Feather.*— Mr. R. S. Wray 

 came to the results which he has reached with regard to the structure 

 of a typical pennaceous feather, while preparing a model for the Natural 

 History Museum. A feather was soaked in turpentine and bits of the 

 vane were cut out and mounted in Canada balsam to show the upper and 

 lower surfaces. Separate barbs were mounted, the barbules on some 

 being teased out with needles, and on others the barbules were cut off 

 by placing a sharp razor on the sides of the barb and pressing gently 

 on the slide, when sufficiently perfect barbules of each kind were 

 obtained for examination. Portions of the vane were carefully imbedded 

 in paraffin, and sections mounted by the creosote-shellac method, so that 

 the parts were obtained in their relative, natural, and undisturbed 

 positions. In addition to transverse and horizontal, sections parallel to 

 the distal barbules were made. A gutta-percba model illustrating the 

 points elucidated by Mr. Wray, is to be seen in the " index-museum " 

 of the Natural History Museum, and is worthy of the attention of 

 microscopists. 



Mounting Tape-worms-f — Mr. W. S. Jackman states that a joint or 

 segment of tape-worm mounted in the following manner will show the 

 ovaries and eggs very clearly. 



Procure good-sized specimens with well-filled ovaries. Remove the 

 alcohol in which they have been hardened, wash and immerse in glycerin 

 for a few days until clear and pulpy in appearance. Place between two 

 strips of glass and squeeze until the specimen is quite thin. Clamp 

 with a stiff spring and allow it to remain thus for several hours — a day is 

 not too long ; sufficient glycerin will adhere to the glass to keep it moist. 

 Next place it in the stain, a few minutes will usually be long enough ; 

 pass it then through the fixing solution and place in oil of cloves, allow 

 it to remain here until the tissue around the eggs assumes a transparent 

 glassy appearance, then remove to a thin balsam solution and mount. 

 Turpentine should not be used for clearing, as it makes the specimens 

 opaque. " Hard finish " answers as well as balsam, is pleasanter to 

 handle, and easier to prepare. It should be thinned with benzol and 

 then filtered. 



Reeves's Method.^ — Mr. R. N. Reynolds states that by following 

 Dr. J. E. Reeves's method of preparing, cutting, and mounting patho- 

 logical specimens he has now great success. The sections are 1/4000 

 in. thick, but only about half or one-third come from under the 

 flattener in a condition to mount. Instead of balsam he uses Berry 

 Bros', oil finish. Sections 1/2000 in. thick came out straight enough 

 for mounting. The chief difficulty in the method arises from not using 

 sufficiently hard paraffin. The author found that the hardest refined 

 paraffin of the Standard Oil Company, Cleveland, supplied the want, 

 but in very cold weather a softer variety could be used. If the 



* Ibis, 1887, pp. 422-3. t The Microscope, viii. (1888) pp. 5-6. 



\ Ibid., p. 31. 



