ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 735 



The operator may be reminded that the material, even from a con- 

 Biderable number of stomachs, is of course very small in quantity, and 

 must be handled carefully, and, as the most beautiful forms are often 

 the lightest, it is of the utmost importance to let the deposit settle 

 thoroughly in the washings of the lighter portions of the gatherings. 

 The water holding the diatoms in suspension should be allowed to 

 stand at least half-an-hour for every inch of its depth, and hence 

 time will be saved by using watch-glasses and shallow dishes for the 

 purpose. 



Bayberry Tallow for Imbedding.* — This substance is obtained 

 from the ordinary bayberry-bush, and is used by furniture manu- 

 facturers for oiling the sliding surfaces of bureau-drawers, &c. It is 

 claimed for the bayberry-tallow that it is cheaper and better than 

 celloidin, and far superior to paraf&n and other kinds of wax hereto- 

 fore used. A special feature claimed for it is non-solubility in 

 alcohol, except when warmed to about the temperature of the body or 

 a little above it, and hence the specimens may be kept indefinitely in 

 alcohol at ordinary temperatures. Another point to the credit of the 

 tallow is that tissues injected with it or imbedded in it can be shaved 

 in thinner sections than those allowed by other materials, and that 

 on account of its firmness it allows of a more even cut. After making 

 a section the tallow may be removed from the specimen by simply 

 placing it for a few minutes in a bath of warm alcohol. 



Imbedding and Examining Trematodes. — Dr. P. M. Fischer t 

 recommends soap, fifteen parts dissolved in 17 "5 parts of alcohol 

 (96 per cent.) as a good imbedding medium for Oj/isthotrema cochleare. 

 Glycerin is used in the examination of the sections. The whole 

 animal can be hardened in absolute alcohol, stained with j)icro-carmine, 

 logwood, or ammonia-carmine, clarified in oil of cloves, and mounted 

 in Canada balsam in chloroform. 



For the investigation of the embryonic sheath of living Cercarice 

 in snails. Dr. J. Biehringer | employs the blood-fluid of the snail it- 

 self. Many facts, e. g. the origin of the accessory membrane of tho 

 sporocyst, can only bo brought to light in this way. 



Hatfield's Rotary Section-cutter.§ — Eev. J. J. B. Hatfield's 

 section-cutter is rotary in all its moving parts except tlie si)ecimen- 

 carricr in its approach to the knife, and the horizontal frame A, 

 supported by the standard B, the lower end of which is a clamp C, 

 for fastening on a table near a corner to give the driving-wheel 

 clearanco. 



D is the circular knife, mounted on tho shaft E, which is rotated 

 by the pulley G and belt F, from the driving-wheel II. I is a hollow 

 shaft, and contains the nut and feed-screw. On tho free end of tho 



♦ Amcr. Mod. Micr. Jonrn., vi. (188.5) p. t)8 (from 'Louisville Med. News'). 



t Zeit.-i^^lir. f. Wiss. Zool., xl. (1881) pp. 1-11 (1 p].). See tiiis Journiil, iv. 

 (1884)p. :^.81. 



♦ Arbr.it. Zn(A.-Z(x>t. Iribt. Wiirzburj,', vii. (1881) pp. 1-28 (1 pi.). See tliia 

 .loiniiiil, iv. (1S81) p. .571. 



§ I'roc. Aiiicr. Hoc. Mi<.r., 7tli Ami. ."\IcLtiii;,', 1881, ])p. 171-2 (2 figw.). 



