590 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



for improving the definition of imperfectly corrected objectives. Red, 

 orange, yellow, aud blue filters are also made. 



Fig. F2D. 



(6) Miscellaneous. 



Cheyney, J. S. — On the Proper Thickness of Cover-Glass. 



Micr. Ball, 1901, Feb. p. 1. 

 Z eiss, 0. — Ein neuer beweglicher Objecttisch. (A new Movable Objert-stage.) 



Zeitschr. f. Instrumentenk., XX. (190H) p. 325. 



B. Technique.* 

 (2) Preparing' Objects. 



Fixation of Embryonic and Young Cartilage.f — As well as the 

 ordinary fixatives, E. Retterer uses the following solutions for observing 

 transitional stages of cartilage. Mixture A : 8 p.c. chromic acid solution 

 66 vols. ; formol 33 vols. ; acetic acid 8 vols. Mixture B : 5 p.c. plati- 

 num chloride solution 5(Tvols. ; formol 50 vols. ; acetic acid 3 vols. 

 Fresh rib cartilages of young animals, guinea-pigs, rabbits, or cats, were 

 immersed in one or other of these solutions for 6 to 12 hours. They were 

 then washed in water, dehydrated in alcohol, and treated for sectioning 

 in the usual manner. 



Fixing Flagellata.^ — H. Plenge fixes Flagellata in the following- 

 ways. A drop of the culture fluid containing Flagellata is pipetted on 

 to a slide and spread out into a thin layer. The organisms are then 

 killed with osmic acid vapour or by the addition of a drop of 1 p.c. 

 osmic acid solution to the water. A cover-glass provided with four wax 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Imbedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c. ; 

 (6) Miscellaneous. 



t Journ. Anat. et Phys., xxxvi. (1900). See Zeitschr. wiss. Mikr., xviii. (1901) 

 pp. 71-3. X Zeitschr. angew. Mikr., vii. (1901) pp. 19-20. 



