ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 213 



shaken, and the contents poured into Petri dishes, which, after setting, 

 were inverted, and inoculated at the requisite temperature (15°, 18°, or 

 22"). When the colonies were sufficiently grown, inoculations were 

 made upon agar slopes and in gelatin stabs. When a pure culture was 

 obtained inoculations were made on many other media. 



i(3) Cutting-, including- Imbedding- -and Microtomes. 



Irrigating Apparatus for Celloidin Sectioning. * — Dr. P. M. 

 Hickey devised an irrigating apparatus (figs. 32, 33), the essential 

 points being a modified oil-cup such as is used in automatic machinery, 

 and the attachment of this cup by means of a suitable support to the 

 sliding block which carries the knife. In this way the alcohol can be 

 dropped on any part of the knife. By means of the needle plunger in 

 the cup the number of drops per minute can be regulated to a nicety. 



Method of Procuring Ribands with a Microtome working Hori- 

 zontally.f — C. Brookover made ribands of sections with a sliding micro- 

 tome, by placing the edge of the knife parallel to the surface of the block 

 to be cut. On that part of the knife where the cutting was to be done, 

 a visiting-card was placed to receive the riband. The card was pierced 

 by two pins sticking down over the back to keep the card from sliding 

 out of position and over the edge of the knife. In transferring the 

 ribands from the card, it is advisable to place the slide over the card, so 

 as to be able to see the sections while they are arranged. 



Imbedding in Celloidin. J — Herr Pokrowski dehydrates pieces of 

 tissue which have previously been in alcohol above 55° by means of 

 ether. The procedure depends on the fact that ether is miscible with 

 alcohol of 55°. In this way the alcohol along with the water is extracted 

 and replaced by ether. It is not necessary to use much ether at a time, 

 but it is preferable to change it frequently. The extraction of all 

 the water may be demonstrated by the fuchsin test. Fuchsin being 

 insoluble in ether the slightest trace will stain the fluid if any water 

 remain. In this way tissue may be more rapidly dehydrated than if 

 alcohol had also been used. The dehydrated pieces may be at once 

 transferred to thin and afterwards to thick ethereal solutions of cel- 

 loidin. Blocks prepared in this way must not be kept in alcohol but in 

 ether to which chloroform (\ vol.) has been added. 



(4) Staining- and Injecting-. 



Simple Method for Staining Bacterial Flagellar — Sig. De Bossi 

 has obtained most excellent results from the following method. An 

 agar culture less than four days old is used. A minute particle is diluted 

 in a little distilled water, and from this a second dilution in rr-1 ccm. 

 of distilled water is made. A loopful is placed on a cover-glass and dried 

 in a sulphuric acid exsiccator. The mordant consists of a solution com- 

 posed of tannic acid 25 grm. and 1 per cent. KHO 100 grm. The stain 



* Journ. Applied Microscopy, iii. (1900) pp. 994-5 (2 figs.). 



t Tom. cit.. pp. 987-8 (3 figs.). 



X Mediz. Obosrenie, 1900, Mai. See Zeitschr. wiss. Mikr., xvii. (1900) pp. 331-3. 



§ Arch, per le Sci. Med., xxiv. No. 15. See Brit. Med. Journ., 1901, i. Epit. 36. 



