ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



519 



that when broth cultures are to be kept more than a month, only iron 

 vessels should be used. Tinned iron, nickel-plated or zinc-plated iron 

 vessels are quite unsuited for bacterial purposes. Copper vessels should 

 be used only for a very short time for preserving sterilised broth. 



T (2) Preparing- Objects. 



Formaldehyde as a Killing and Fixing Agent. * — Prof. T. P. 

 Carter has found that the following formula yields most satisfactory 

 results'., when used for killing and fixing : — formaldehyde, 40 per cent, 

 solution, 50 ccm. ; distilled water, 50 ccm. ; glacial acetic acid, 5 ccm. 



By this solution tissues are killed and fixed in from 6-12 hours, but 

 the immersion may be continued for 24 hours without damage. The 

 pieces are then transferred to 50 per cent, alcohol for one hour, and 

 afterwards to 75 per cent, and 95 per cent, alcohol for half an hour each. 



Method of Examining Red Blood-corpuscles, f — Sig. A. Negri, 

 in his researches on the nucleus of mammalian red corpuscles, adopted 

 Petrone's method. The best results were obtained by removing the 

 blood (man and rabbit) along with osmic acid 1 : 4000, placing it in 

 picric acid 1 : 4000, and then staining with formic acid carmine. From 

 the appearances observed the author arrives at the conclusion that the 

 forms described by Petrone are not to be regarded as nuclei. 



Apparatus for rapidly Dehydrating Pieces of Tissue. J — Herr 

 M. Pokrowsski describes a small apparatus (fig. 137) intended for dehy- 

 drating pieces of tissue as rapidly as possible. 

 The essential part of this contrivance, as will 

 be seen from the illustration, resembles a wine- 

 glass in shape, the cup of which is perforated 

 with numerous holes. In lieu of perforated 

 metal the cup may be made of wire sieve. The 

 apparatus is placed within a large glass vessel 

 which is filled with alcohol or some other 

 hardening fluid, and the tissue to be hardened 

 is located in the cup. 



New Maceration Medium for Vegetable 

 Tissue. § — Herr O. Richter finds that strong 

 ammonia will macerate vegetable tissue without 

 injury to the cell contents such as starch and 

 aleurone-grains, chlorophyll granules, &c. The 

 fluid was used boiling, cold, and at a temperature 

 of about 40° C. The rapidity of the maceration 

 depends on the temperature. 



Preparation of Conceptacles of Fucus.)| — 

 M. J. Chalon finds that male and female carpomates (conceptacles) of 

 Fucus vesiculosus and serratus can be preserved indefinitely in strong 



* Amer. Mon. Micr. Journ., xxi. (1900) pp. 93-6 (1 pi.), 

 t Anat. Anzeig., xvi. (1899) pp. 33-8 (9 figs.). 



% Medizinsskoe Obosrenie, Sept. 1899, 3 pp. and 1 fig. See Zeitschr. f. wiss. 

 Mikroskopie, xvii. (1900) pp. 38-9 (1 fig.). 

 § Oesterr. Bot. Zeitschr., lv. (1900) p. 5. 

 || Bull. Soc. Beige de Microscopie, xxv. (1898-9) pp. 107-9. 



Fig. 137. 



