ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 737 



are stained by a 1 p.c. solution of magenta-red in half an hour, and then 

 differentiated for a similar length of time. Sections of Pontobdella take 

 an hour to stain, but are differentiated in from 10-15 minutes. 



Demonstrating the Presence of Negri's Bodies in Hydrophobia.* 

 Anna W. Williams and May M. Lowden demonstrated the presence of 

 Negri's bodies in the following way. Smears were made from the 

 cerebral cortex of the Ptolandic region, the cornu ammonis, and the 

 cerebellum. The smears were air-dried, and then fixed in methyl-alcohol. 

 Some were stained by Giemsa's method (azur ii.-eosin, 3 ; azur ii., • 8 ; 

 glycerin and methyl-alcohol, 250 each ; the glycerin and alcohol are 

 heated to 60° ; the pigments are then dissolved in the alcohol and the 

 glycerin added slowly, stirring the while. After standing all night, the 

 mixture is filtered, and the solution is then ready for use. One drop of 

 the stain to every c.cm. of distilled water made alkaline by the previous 

 addition of one drop of a 1 p.c. solution of potassium carbonate to 

 10 c.cm. of the water). The solution made in the foregoing manner is 

 poured over the smear and allowed to act for |— 3 hours, or even 

 much longer. The excess stain is removed with tap-water ; the smear is 

 then dried with blotting-paper. 



Other smears were treated by Mallory's eosin-methylen-blue method : 

 The smears are fixed in Zenker's solution for ^ hour, and after rinsing 

 in tap- water are placed successively in 95 p.c. alcohol -f iodin, 4/ hour ; 

 95 p.c. alcohol, ^ hour ; absolute alcohol, \ hour ; eosin solution, 20 

 minutes ; rinsed in tap-water ; methylen-blue solution, 15 minutes ; 

 95 p.c. alcohol, 1-5 minutes ; and then mopped up with filter-paper. 



For sections the technique was as follows : — Fixation in Zenker's 

 fluid for 3-4 hours ; tap-water, 5 minutes ; iodin-alcohol, 24-48 hours ; 

 95 p.c. alcohol, 24 hours ; absolute alcohol, 4-G hours ; cedar-oil ; cedar- 

 oil + paraffin 52°, 2 hours ; paraffin 52°, 2 hours. Sections 3-6 /a thick 

 were dried in incubator at 36° for 24 hours, and stained by Mallory's 

 eosin-methylen-blue method. 



As depicted in the illustrations, the bodies stained by Mallory's 

 method are red with one or more blue granules ; by the Giemsa method 

 there is a thin peripheral zone of pink, inside this the body is bluish, the 

 granules with which it is beset being red. 



(5) Mounting-, including Slides, Preservative Fluids, &c. 



New Method of Mounting Fungi grown in cultures for the 

 Herbarium.t — Gr. O. Hedgcock and P. Spaulding separate the fungi, 

 and make pure cultures in Petri dishes upon a rather stiff agar made 

 with some infusion suitable for the normal growth of the fungi. At the 

 proper stage in their growth the plates are divided into square blocks of 

 agar of a suitable size. Each of these blocks is placed right side up on 

 stiff cardboard, and allowed to dry down. After the agar has become 

 dry the mount is protected by pasting over the agar block a small square 

 or circular piece of cardboard which has been perforated with a gun-wad 

 cutter, the perforation being of a size necessary to include the mounted 



* Journ. Infectious Diseases, iii. (1906) pp. 452-83 (4 pis.), 

 f Journ. Mycol., xii. (1906) p. 147. 



