1 
Journal of Proceedings. 
putting the cell together. The upper (or perforated) plate is made shorter 
than the lower one, so as to avoid the danger of the plates being pressed 
together unequally, and the thin glass or talc crushed, when the 
apparatus is taken up by one end. A slip of thin glass can be placed 
inside the cell behind the piece of weed or Conferva bearing the organism 
for examination, and kept close up to the front thin-glass plate by a 
Fig. 3.—Thomas’s Vivarium, No. 1. 
Fig. 4.—Thomas’s Vivarium, No. 2. 
wedge of cork or paper (as shown in No. 1), so as to bring the object 
within the compass of the highest powers. (See Journ. Hoy. Micros. 
Soc., 2nd series, vol. ii., p. 688). 
