228 THE MICROSCOPE. [November, 



THE Vv^ORKERS 



Radiolaria: Their Life-History and Their Classification. 



Rev. Fred'k B. Carter has described the Radiolaria in an 

 extended article which has appeared in the American Alonthly 

 Microscopical yournal during the year 1S92. The article, 

 which was begun in the Alarch issue and ended in the November 

 Joiir7ial^ cannot fail to interest all students of the Radiolaria. 

 Among other things, Mr. Carter says, in the November article : 



h. word or two more about the preparation and mounting of these 

 forms. I have given the simplest method, but if the student 

 becomes interested he will not be satisfied with that. The forms 

 will not be clean enough to suit him. After trying various meth- 

 ods, at the suggestion of a correspondent I tried that used by 

 Terry in cleaning diatoms, and described in a former number or 

 the Journal, only instead of mixing bi-chromate of potash with 

 the material and then adding sulphuric acid, I use chromic acid, 

 which gives good results and is simpler. Buy th-e crystals of 

 chromic acid and dissolve in water as you need them. Then take 

 the material which has been partially cleaned by the process I 

 mentioned and put it in an evaporating dish, pouring off as much 

 of the water as possible. Heat the bottle of chromic acid by let- 

 ing it stand a minute or two in hot water. Heat the material also 

 in the evaporating dish over the spirit lamp. Then add the 

 chromic acid and let it stand a few minutes, keeping up the heat 

 by the spirit lamp. Then pour the material into quite a quantity 

 of water in a high glass and let it settle. Wash until all the yellow 

 color disappears. Then let the material settle in a test-tube, pour 

 off as much of the water as possible and cover with strong am- 

 monia. Then wash several times again. If the forms are not 

 then clean enough repeat the process and keep on repeating till 

 they come out as you wish. 



And now, in conclusion, let me say that I am certain there is a 

 vast amount of pleasure in store here for any young microscopist. 

 With many a beginner the question is, what special line to take 

 up. And even many a microscopist of long standing and larger 

 experience is at times at a loss as to what he shall make a sub- 

 ject of close investigation. If any of you are in that state, or ever 



