Peck n. Harrington, Plankton des Puget-Sound. 



is indeed an escape of fine bubbles from the contents of the jar be- 

 cause of the diminishing pressure in its ascent, and we believe that 

 the displacement from a full jar through so small a column of water 

 as fills the tube is corrected by simply emptying the tube and neck 

 of the jar as soon as it is received, and that there is then a represen- 

 tative sample secured by this means. The apparatus was tested each 

 time by lowering- it to the bottom and returning- it without breaking 

 the tube, and it was found that its strength was sufficient. Great 

 care is necessary in the adjustment of the cork before lowering- as 

 the pressure at considerable depths is very great. 



Plotting to show vertical distribution of fine elements of 

 Plankton in 112 fathoms. Surface bottom and three intermediate levels 

 are represented by the horizontal lines upon which are laid off widths, corre- 

 sponding to the numbers taken in each case. These widths at the various levels 

 are made the basis for the construction of the several columns which show 

 the facts of distribution. On the first column the black area denotes living 

 portion and the stippled area the larger species. On the second column, 

 black area denotes living portion and the oblique -lined areas the dead and 

 mutilated parts, while the small white bars in the black areas denote the 

 separation of the two type species. On the third column the attempt is made 



to show distinction of dead and living material. 



QQ * 

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