662 SUMMARY OF CURRENT RESEARCHES RELATING TO 



ground substance was unstained, while the cell elements autl their jiro- 

 longations remained of a bright red hue. This staining was tixed by 

 immersing the sections for some hours in a one per cent, solution of 

 alum. They were then examined, and mounted in the alum solution, 

 wliieh must be sterilized. The prolongations of adjacent cells wero 

 found to anastomose. 



Preparing Mammalian Ovaries.* — From his investigation on the 

 ovaries of mammalia Prof. G. Pahulino finds that these organs are the 

 seat of a continuous movement of destruction and renovation, and furtlier, 

 that in the formation of the ovules, the regeneration of the parenchyma, 

 the development of the follicles, and in the production of the corpora 

 lutea, karyokincsis occiirs freely. 



For hardening the ovaries the author used a 2-4 per cent, bichromate 

 of potash solution, Miiller's fluid, 1/2 to 1 per cent, osmic acid, saturated 

 aqueous solution of sublimate, 2 per cent, chromic acid, and also 

 Flemming's chrom-osmium acetic acid. The staining seems to have been 

 eifected entirely with picro-carminate of ammonia, of which two solutions 

 were used, a 1 and 2 per cent. The pieces were placed in these solutions 

 ftT a short time only, and then transferred to very dilute solution of 

 picric acid. The jiieces were always completely freed from the hardening 

 fluids, and rendered neutral as the neutral reaction is indispensable for 

 properly staining the nucleus. 



Preparing and Staining Annelida.f — M. E. Jourdan found that 90° 

 alcohol and picric acid gave very bad results in examination of Annelida ; 

 the tissues being crumpled and their elements unrecognizable. From 

 bichromate of ammonia in 2 per cent, solution, sublimate in 5 per cent., 

 or a saturated solution and Lang's fluid, beautiful preparations were 

 obtained. One per cent, solution of osmic acid was found to give excel- 

 lent results for examining antenna) and other delicate organs. After 

 fixation in the above-mentioned fluids, the preparations were hardened 

 in spirit. The objects were stained with carmine solution, principally 

 with Grenacher's alum-carmine, and were imbedded in celloidiu or in 

 parafiin. The sections, which were stuck on by Schiillibaum's method, 

 were, for studying gland-cells, stained with ha^matoxylin eosiu and with 

 Hofi'mann's green. 



Preparing Polygordius.| — Dr. J- Fraipont hardens the entire animal 

 in 1 per cent osmic acid, washes with water, stains with ammoniacal 

 picrocarmine, and after treating with alcohol and turpentine oil mounts 

 iu balsam. 



Macerated specimens are prepared in 40 per cent, spirit for 36 to 48 

 hours, or still better in chromic acid 1/10000 for 24 hours. Besides 

 employing the usual methods for macerated specimens, the author found 

 it also advisable to squeeze half macerated parts between cover-glass and 

 slide, by which the separated parts and their relation to one another 

 were recognizable. Living animals treated with 1 per cent, gold chloride 

 and citric acid, and afterwards teased out, is not a very easy method, but 

 sometimes gives very instructive pictures. The macerated parts can be 



* ' Ulteriore ricerclie suUa distruzione e rinnovaraento continuo del parenchyma 

 ovarico nci mammiferi : nuove contribiizioui alia inorfologia e fisiologia dell'ovaja.' 

 8vo, Naples. 1887, 280 pp. (0 pis.). Cf. Journ. tie Miciogr., xii. (1888) pp. 223-6. 



t Ann. ScL. Nat. (Zoul.), ii. (1887) pp. 239-304 (5 pis.). 



J Fauna u. Flora d. Golfes von Neapcl, xiv. (1887) 125 pp. (16 pis. ;mJ 1 fig). 



