,(>- SUMMARY OF CURRENT RESEARCHES RELATING TO 



hematoxylin, or R. Heidenh;iin*s hematoxylin potassium chromate is 

 especially useful. Referring to the borax-carmine stain, he notes that 

 ilif nuclei <if the Branchiopods have very little stainable substance, so 

 that he stained the object for about 48 hours at : J >5°-40°C. 



For decolorising the eyes he uses free chlorine by a modification of 

 Mayer's method ; he fills a test-tube with 96 p.c. alcohol, adds a few 

 drops of nitric acid, and puts a couple of crystals of potassium chlorate 

 into the mixture ; into the lower half of the tube he dips a thin layer 

 of wool, and lays it on the head of the animal, which had been pre- 

 viously kept in 70 p.c. alcohol ; in this way the object does not rest 

 on the potassium chlorate ; in 12-24 hours at room temperature, the 

 pigment will be completely removed from the tissue, which has not 

 suffered any marked alteration from the treatment. 



Investigating the Anatomy and Development of the Venous 

 System of Chelonia.* — F. A. Stromson killed the turtles with chloral 

 hydrate, and injected through the left abdominal vein. The best results 

 were obtained when the animals were killed several days before injecting 

 them. The mass used was mostly gelatin, and in order to prevent it 

 cooling before all the veins were filled, the specimens were previously 

 placed in warm water. If, however, iodide of potassium is used to 

 lower the melting-point of the gelatin, this is not necessary. Some of 

 the turtles were injected with Huntington's wax-mass, and corroded 

 with strong hydrochloric acid. 



The material used for studying the development of the veins of 

 embryos was fixed in picro-sublimate. The embryos were dehydrated, 

 cleared, and imbedded in paraffin, and serial sections were cut about 

 20 fx thick. The best staining results were obtained from Delafield's 

 haematoxylin and picric acid. Reconstruction methods were freely used. 



Demonstrating the Structure of Gutta-percha Plants.f — A.Charlier, 

 when investigating the anatomy of gutta-percha plants, used collodion 

 sections of the leaf, and stained them with acetic orcanette, with orcanette 

 and chloral, or with sudan, in order to demonstrate the lacticiferous net- 

 work. It was found easy to macerate little bits of leaf in eau-de-favelle, 

 and, after carefully washing in dilute acetic acid, to stain the tissue en 

 masse. The maceration in the hypochlorite varied according to the 

 thickness of the leaf, from 24 hours to several days. These preparations 

 were mounted in glycerin-gelatin. 



In order to study the walls of the lacticiferous vessels, the latex was 

 got rid of by immersing the sections in chloroform. The sections were 

 then cleared up in hypochlorite and afterwards stained with iodine- 

 green and alum-carmine. Bismarck brown and Delafield's haematoxylin 

 gave equally good results. 



Demonstrating the Structure of the Respiratory Tract of Birds.:}: 

 For demonstrating the bronchial ramifications of birds, G. Fischer made 

 corrosive preparations by the aid of wax-masses, celloidin, photoxylin, 

 and celluloid solutions. 



* Amer. Journ. Anat, iv. (1905) pp. 453-4. 



t Journ. Bot., xix. (1905) pp. 183-4. 



X Zoologica, xix. (1905) 45 pp.. 5 pis. nnd 2 figs in text. 



