94 Animal Microloyy 



adjusted by pulling the hair. After the slide is finished and dry, the 

 ends of the hair should be cut off at the edge of the cell. 



Another method which will frequently answer for an object to be 

 mounted in balsam is to place the object (after clearing) in the center of 

 the cell, coat it with balsam, adjust it properly, and then set the slide 

 away in a place free from dust till the balsam thickens. Finally fill the 

 cell with balsam and add the cover. 



7. The Radula or Lingual Ribbon of the Snail or Slug should be dissected 

 out and soaked for a day or two in a 10 per cent, solution of potash. If 

 the animal is a small one, cut off the head including the buccal mass 

 and soak it in a solution of potash until the soft tissues are destroyed 

 and only the radula remains. From the potash the radula is transferred 

 to water and washed for some hours. With a strip of paper on each 

 side to prevent crushing it, it should be placed between two slides, and 

 the slides bound together by means of string or rubber bands. While 

 held in this position, dehydrate and clear it. Finally remove one slide 

 and the paper and mount the object in balsam on the other slide. A 

 shallow cell may be used if desired. 



8. Flukes and Tapeworms are prepared in the same manner as planaria 

 (see IV, A). The time of immersion in the various fluids should be 

 lengthened in proportion as the object is larger than the planarian. 

 See also Appendix D. 



9. Spirogyra, Protococcus, Volvox, Desmids, etc., may be mounted in a 

 cell in the following copper solution : 



Acetate of copper 1. gram 



Camphor water 240. c.c. 



Glycerin 240. c.c. 



Glacial acetic acid 0.3 c.c. 



Corrosive sublimate, saturated aqueous solution 0.1 c.c. 



Mix thoroughly, filter and keep in a glass-stoppered bottle. The green 

 color of the plant may frequently be preserved for some time in this 

 medium. The specimen is washed in water, transferred to the cell, then 

 the solution is added. The cell is covered and sealed in the usual way. 



10. A Dipping-Tube is a simple glass tube. To operate it, hold the 

 tip of the forefinger over the upper end and dip the lower end into the 

 water until it comes just above the object desired; lift the finger and let 

 the air out of the tube, and the water will rush in at the lower end carry- 

 ing the object with it. Replace the finger over the top of the tube and 

 remove it; the water will remain in it as long as the finger is held firmly 

 over the upper end. When the finger is removed the water and tin- 

 object pass out. The object may sometimes be more readily discharged 

 if the tube is rotated. 



