Figure 23. — Pouring plankton and preservative into 

 draining cone is the third step of measuring plankton 

 volume. The cone (333-/i nylon mesh — see Table 1 for 

 source of specifications) retains the plankton; the cyl- 

 inder receives the fluid. Large sewing needles suspend 

 cone in funnel keeping mesh from touching funnel's sides 

 and allowing proper drainage. 



which the organisms will be sorted. These 

 dishes are aligned on one side of the mi- 

 croscope. On the other side of the micro- 

 scope are a number of Syracuse dishes, each 

 labelled on its ground-glass surface with 

 the name of the organism which will be 

 transferred to it when sorted (Fig. 2.5). 

 Each of the labelled dishes is about half full 

 of 3 to 5% buffered Formalin. (In this in- 

 stance, the few dishes of such Formalin are 

 not enough to affect the sorters adversely. ) 

 3. Using a binocular, dissecting microscope, 

 usually at a total of 9X power, with trans- 



Figure 24. — Reading volume is the fourth step of mea- 

 suring plankton preservative after plankton has drained 

 to an occasional drop. The volume of the calibrated jar, 

 holding plankton and preservative (Fig. 20), less the 

 volume in the cylinder equals the displacement volume 

 of the plankton. The cylinder is plastic tubing, 1-1/2 

 inches I.D. X 34 inches long (3.8 X 86.4 cm) with grad- 

 uations etched on the cylinder or on a grooved board, as 

 illustrated. The graduations on cylinder or on the board 

 are 5-ml units from 0-600 ml and 2-ml units from 600- 

 910 ml. Volumes are read to the nearest millimeter. 



24 



