872 THE AMERICAN NA TURALIST. [Vol. XXXVII. 



of an average college. But an apparatus that will do all these 

 things and that will gather in a few minutes use more plankton 

 than can be even qualitatively examined in a laboratory period, 



College at a cost ofabout ten dollars. 



The exterior of the apparatus is shown in Fig. 2 and the 

 net itself is seen in the second figure of the plate. A net of the 

 usual form was made of no. 20 silk bolting cloth. A large milk 

 can with loose breast and heavy steel cap was used to sustain the 

 net and to hold the slack water in which it should rest while 



