134 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



Staining and Fixing- Spore-mother-3ells of Anthoceros.* — Mr. 

 Bradley M. Davis makes the following notes on various processes in 

 the case of this representative of the Hepaticae. 



Chromacetic acid fixes filarplasm, bnt the safranin stains diffusely- 

 after it, and gent'.an-violet does not hold well in the spindle-fibres. If 

 sections fastened tv) the slide are left several days in weak Flemming, the 

 staining qualities with safranin and gentian-violet are much improved. 

 Merkel's fluid (I per cent, chromic acid 12 ccm., 1 per cent, platinum 



Fig. 34. 



Fig. 35. 



<n— T*" 



7_e% 



chloride 12 ccm., water 72 ccm.), even when used for long periods 

 (36 hours), is thoroughly unsatisfactory; the spindles are badly fixed. 

 Boveri's picro-acetic acid gives beautifully bleached tissue, but achro- 

 matic regions are not clearly differentiated, although chromatic elements 

 stain well. Sublimate-acetic (5 per cent, glacial acetic acid in saturated 

 solution of corrosive sublimate) is not good ; nuclear membranes and 

 filarplasm are very poorly preserved. Hermann's fluid is very much 

 like Flemming's in its effects, and is thoroughly satisfactory. The 

 osmic acid of the Flemming's and Hermann's mixtures appears to give 

 them certain advantages over all other fluids. 



Photochemical Methods of Staining Mucilaginous Plants.f — Mr. 

 A. Lundie stains mucilaginous plants by the chromatype method, using 

 a saturated solution of potassium bichromate mixed with one-twentieth 

 of its volume of saturated cobalt nitrate solution. A piece of an alga, 

 Batrachospermum for example, is suspended in this mixture in a glass 

 tube, and exposed to diffuse daylight for 30 minutes. It is then 

 transferred to a slide, treated wiih silver nitrate solution, and again 

 exposed to light for five minutes. The nitrate is now removed, and an 



* Bot. Gazette, xxviii. (1899) pp. 105-6. Cf. supra, p. 88. 

 + Trans, and Proc. Bot Soc. Edin., xxi. (1S99) pp. 159-62. 



