624 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tannin-orange. Good results were also obtained with Leislnnan's stain 

 and with a modification of Gienisa's solution, using a 1 p.c. aqueous 

 solution of azur ii. and ■ 1 p.c. aqueous solution of erythrosin mixed on 

 the slide after fixation with pure methyl-alcohol. 



Other blood films and smears of organs were fixed with a mixture of 

 sublimate 2 parts and absolute alcohol 1 part, or with osmic acid, and 

 then stained with a dilute acidulated solution of Delafield's hsenia- 

 toxylin followed by eosin. The staining is slow, at least 24 hours being 

 necessary. 



Demonstrating Segmentary Organs of Polychsete Annelids.* — 

 L. Fage attained the best results, in his researches on the Polychajte 

 Annelids, by means of fine dissection under the Microscope. In order 

 to facilitate the operation, the coeloin was injected with indian ink or 

 carmin, or by treating the specimen from which the digestive tube had 

 been removed with a very dilute solution of neutral-red in sea-water. 



Control observations were made from sections of material fixed with 

 a saturated solution of sublimate in sea-water, to which 5-10 p.c. acetic 

 acid were added. Bouin's and Tellyesnicky's fluids gave equally good 

 results. For special purposes, Lindsay's, Flemming's, and Merkel's 

 fluids were used. Paraffin sections were made in the usual way, and 

 stuck to the slide with a ^^ gelatin solution in water. The stains 

 used were alum-carmin, iron-kamiatoxylin, and, after osmic acid fixatives, 

 magenta-red or safranin. As plasma stains, light green and orange G 

 were used. 



Special methods were adopted to bring out the reticulum of the 

 phagocytic organs and the secretory vesicles. For the former the pieces 

 were macerated in a weak solution of bichromate of potassium, or in 

 Merkel's fluid. 



A selective staining of the secretory vesicles was obtained by treat- 

 ing the sections after the manner of Weigert. 



Demonstrating Chromatic or Nucleoid Granules.! — N. Loewenthal 

 fixes the material in Flemming's solution, and stains the sections with 

 paraffin, afterwards decolorising with alcohol acidulated with hydro- 

 chloric acid. 



Zenker's fluid followed by hematoxylin and eosin was also used, 

 except for the cerebro-spinal ganglia, which were fixed either in chrom- 

 osmic-acetic acid or in Erlicki's fluid ; staining in the former instance 

 being effected with safranin, in the latter with picro-carmin or hgemato- 

 xylin. 



Part played by Sodium Chloride in the Silver Impregnation 

 Method. J^ — Ch. Achard and M. Agnaud support the view recently put 

 forward by Quinton that the reduction of the silver in the tissues is 

 due to the presence of sodium chloride in the intercellular spaces, 

 and the formation of a precipitate of silver chloride, which turns black 

 on exposure to the light. The authors find that if the sodium chloride 

 be removed by immersing the membrane in a solution of sodium sul- 



* Ann. Sci. Nat. Zool., iii. (1906) pp. 261-410 (2 pis.). 

 t Journ. Anat. et Physiol., xlii. (1906) pp. 305-56 (1 pi.). 

 t Comptes Rendus, cxlii. (1906) pp. 1571-2. 



