The standard sub-sampling box is a modified Marchant design consisting of an approximately 27 x 27 x 15 cm box that is divided into 100 cells and has a water tight lid. Wash the sample from the sieve into the Marchant Box and fill with water to a depth just below the height of the walls dividing the cells. Water depth is important. In the case of live samples, water deeper than the dividing walls will allow animals to swim between the cells once the contents have been randomized. Less water will make it difficult to distribute the sample among the 100 cells. Close and fasten the lid. Invert and gently mix the sample with side-to-side rocking motions. Right the box quickly and set on a level surface to let contents settle into cells. Using random numbers for the 10 columns and 10 rows, randomly select one or more cells and transfer contents to a suitable container or Petri Dish using a pipette, vacuum pump or aspirator and suction flask, or similar method.