ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 717 



the vertical distance of the tube G can be regulated. The adjustment 

 of G to the centre of the field is obtained by turning B B. Two 

 sliding clamps C' C' serve to tighten C and B. 



The apparatus can be used either for directing moisture from the 

 mouth on the objects on the slide, and temporarily securing them 

 until finally mounted, or by adding a wire clip at P and pressing the 

 tube T below that point w T ith the thumb and finger, the tube can be 

 used as a syringe, so that it can be made to take up or emit a drop 

 of fluid. 



The flexibility of the tube obviates the danger of any breakage 

 by overpressure of G on the slide. 



Mounting several Groups of small Microscopic Objects under 

 one cover.* — Mr. S. G. Shanks gives the following directions for 

 mounting pollens, which will also suffice for other small objects : — 



The pollens should be gathered from freshly opened flowers, and 

 may be teased from the anthers with a needle into small bottles, 

 which, after the pollen is thoroughly dry, should be kept corked. 



Prepare a card marked with three, four, or five spots, all arranged 

 within the limits of a 3/4 in. cover-glass, place a glass slip upon the 

 card, and put a minute drop of turpentine on the slip over one of the 

 marked spots. A needle with a little turpentine on it will serve to 

 convey a small amount of pollen from the bottle to the drop of turpen- 

 tine on the slip. Cohering masses of pollen should be separated 

 with the needle and spread as evenly as possible over 1/8 in. of space 

 on the slip. A small drop of balsam, just sufficient for the purpose, 

 is then dropped on the pollen. 



The next specimen of pollen is similarly arranged over another 

 spot, and a small drop of balsam applied as before. When the several 

 pollens are in place the slide should be set aside and covered from 

 dust for twenty-four or forty-eight hours, or until the balsam has 

 become somewhat hardened and the pollens fixed in their respective 

 places. A drop of fresh balsam may then be placed in the centre 

 between the groups and a cover applied with very gentle pressure, 

 and all allowed to harden as usual. If the first balsam drops are not 

 sufficiently hard when the cover-glass is adjusted, the fresh balsam 

 will liquefy all too rapidly, and the pollens will run together or creep 

 out with the surplus balsam. Two strong a pressure will also cause 

 the pollens to mix by producing currents in the balsam as the cover 

 settles into place. 



The names of the flowers from which the pollens are gathered 

 should bo written on the label in small characters and occupy the 

 same relative positions as the specimens do under the cover. This 

 will enable one to 6nd a given specimen or name quickly. 



This method may be employed for Foraminifera, seeds, diatoms, 

 scales, or any other small objects which might be placed together for 

 the purpose of comparison. 



Cassia Oil for Mounting'. — This medium has already been recom- 

 mended for immersion and probably also for mounting, though we 



* Amur. Mem. Micr. Journ., vii. (18SG) pp. 64-5. 



