112 SUMMARY OF CURRENT RESEARCHES RELATING TO 



poured. The larger vessel was closed. The euchlorine gas evolved 

 soon oxidised the black deposit of metallic osmium on the tissues. 



In the orientation of sections the postero-lateral arms of the larva; 

 were of the greatest assistance, for they persist until the metamorphosis 

 is quite complete, so that they mark a constant plane amidst the varying 

 position of the other organs. This plane is called the frontal plane, and 

 most of the sections were cut parallel to it. Sections parallel to the 

 median sagittal plane of the larva were also employed, as were transverse 

 sections when they became necessary in order to elucidate special points. 



Studying the Adenoid Tissue of the Spleen, etc.* — C. Ciaccio 

 adopted Levaditi's Spirochceta method for studying the fine structure of 

 the adenoid tissue of the spleen, lymphatic glands, and intestine. He 

 fixed in 10-15 p.c. formalin for 24 hours, and, after a short washlin dis- 

 tilled water, immersed the tissue in 90° C. alcohol for 24 hours. After re- 

 moval of the alcohol in distilled water, the pieces were passed into 1 * 5 p.c. 

 silver nitrate for 3 to 4 days at 38 °C. On removal they were again 

 washed in distilled water, and then placed in the reducing solution, 

 which consisted of 2 p.c. pyrogallic acid plus 15 p.c. formalin. After 

 reduction, the pieces were passed successively through water, alcohols, 

 and xylol to paraffin. The sections were examined unstained and 

 stained : the best staining solution was Pianese's fluid (acid-fuchsin, 

 Martin's yellow, and malachite-green). 



Examining the Trophospongia of Striated Muscle.f — E. Holm- 

 gren examined the striated muscle of Insecta, Crustacea, Amphibia, fish, 

 reptiles, birds, and mammals. At first the author's trichloracetic- 

 resorcin-fuchsin method was employed, but was afterwards supplanted 

 by Golgi's silver-chromium method. The solution consisted of 4 parts 

 of 4 p.c. bichromate of potash and 1 part 1 p.c. osmic acid, the material 

 being immersed therein for 6 to 8 days at 30-31° C. This was followed 

 by 0*75 p.c. silver nitrate solution for 24 to 48 hours at the same 

 temperature. The material was then placed in alcohol, frequently 

 changed, for 24 hours, then xylol, xylol-paraffin, and pure paraffin. 

 Carnoy's and Flemming's fluids were also used, the sections being 

 stained with Heidenhain's iron-hamitoxylin, acid-fuchsin, and picro- 

 carbol-fuchsin. 



Fixation of Insect Larvae. $ — W. D. van Leeuwen has devised a 

 mixture which he has found very useful for fixing insects, especially 

 during metamorphosis. It consists of 1 p.c. picric acid in absolute 

 alcohol 6, chloroform 1, formalin 1, acetic acid \ part, or less. The 

 mixture should be freshly prepared. The insects, pupaj, larvge, imagos 

 are left in the fluid for 24 hours or so, and then transferred to 90 p.c. 

 alcohol for 3 days, and afterwards preserved or further treated in any 

 desired manner. Good sections can be obtained by the benzol-paraffin 

 method. 



* Anat. Anzeig., xxxi. (1907) pp. 594-601 (7 figs.), 

 t Arch. Mikr. Anat., lxxi (1907) pp. 165-247 (8 pis.). 

 \ Zool. Anzeig., xxxii. (1907) pp. 316-20. 



