496 SUMMARY OF CUEKENT RESEARCHES RELATING TO 



(formalin and absolute alcohol) were soaked in water and then immersed 

 in a 1 p.c. solution of tannin, to which pyridine was added in quantity 

 sufficient to redissolve the turbidity. After about a quarter of an hour 

 in this bath at 50°, the pieces were frequently washed in distilled water. 

 The pieces were next placed in a flask containing a 1 p.c. solution of 

 nitrate of silver, to which 10 p.c. of pyridine had been added, and 

 incubated at oO'' for an hour. After a wash in distilled water the pieces 

 were reduced in a 4 p.c. solution of pyrogallic acid, to which as much 

 pyridine had been added as served to render the solution clear. Reduc- 

 tion took only a few minutes. Then distilled water, alcohol, xylol, 

 paraffin, and sections ; the latter were stained with a combination of 

 neutral red and methyl {sic) blue. 



Studying the Spermatogenesis of Blatta germanica.* — A. 

 Wassilieff tixed the testicles in sublimate, sublimate acetic acid, 

 Flemming's and Hermann's solutions, all of which gave good results. 

 Carnoy's, vom Rath's, and Rabl's fluids were unsuccessful. Sublimate 

 preparations stained with iron-hfematoxylin showed the centrosomes 

 well. Mitochondria were excellently shown when iron-hfematoxylin was 

 used after Flemming's fixative. Magenta-indigo-carmin with picric 

 acid (Ramon y Cajal's method) was extremely suitable for the study of 

 chromosomes. The last-mentioned stain was also effective for centro- 

 somes, but useless for mitochondi'ia. As the sexual glands function 

 throughout the year, all stages in the development of the sexual pro- 

 ducts were always obtainable. 



(3) Cutting-, including- Imbeddingr and Microtomes. 



Studying the Nucleus and Kinesis in Spirogyra.f — Jules Berghs 

 fixed the material in Hermann's, Benin's, or in Moll's modification of 

 Flemming's fluid. The material was gathered once in June and once in 

 September, the former at about t) p.m., the latter at midnight ; both 

 collections gave numerous kinetic figures. The different stages in 

 manipulation from the fixative to imbedding in hard paraffin, were very 

 slowly and carefully carried out, a dialyser being used when transferring 

 from aqueous media to alcoiiol. When the chloroform stage was 

 reached it was found expedient to use soft paraffin at first and gradually 

 work up to hard. Most of the sections were stained with Heidenhain's 

 iron-hasmatoxylin, but some with safranin and light green, as advised by 

 Benda. 



Treatment of Celloidin Serial Sections. | — Ino Kubo communi- 

 cates the following procedure. The sections in series are kept till 

 wanted in a glass vessel. Each series is placed on a numbered strip of 

 bibulous paper moistened with alcohol, and this in its turn is inclosed 

 in another piece, which is tied or rolled. 



The slides to be used are first marked with a diamond or with Indian 



* Archive Mikrosk. Anat. u. Entwickl., Ixx. (1907) pp. 1-42 (3 pis.). 



t La Cellule, xxiii. (1906) pp. 53-86 (3 pis.). 



t Archiv Mikrosk. Anat. u. Entwickl., Ixx. (1907) pp. 173-6 (1 fig.). 



