386 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
increased the more simple the appliances of the laboratory. Hence, 
during a short stay at the seashore for the purpose of study of these— 
forms, where the equipment of a hastily constructed laboratory is neces- 
sarily meager, great inconvenience is experienced. 
In order to obviate this difficulty | have used a method which I found 
both simple and satisfactory. Small bags having the shape repre- 
sented in the accompanying figure are made of bolting cloth, a fine 
mesh being used so that the desired organisms can 
not pass through. The organisms having been 
removed by means of an ordinary glass tube from 
the glass dish in which the surface nets were 
emptied, are now transferred to the bag just de- 
scribed. During this manipulation the little bag 
is kept open by means of a pair of forceps in the 
closed by tying astring around itsmouth. Several 
bags filled in this way are then placed in an Erle- 
meyer flask or, in the absence of this, into a com- 
mon wide-mouth bottle. 
A suitable weight, preferably a glass rod, having 
been placed on the bags to prevent them from 
floating, the solution of chromic acid is now poured 
over them and permitted to remain in contact {6r 
twenty-four hours. The bags are then removed, 
and having been attached to a long piece of cord, 
with an interval of 2 or 3 inches between every two 
bags, the whole is tied to any convenient object 
and washed in a stream of water until free from 
the chromic acid. This usually takes about two 
hours. The bags are now removed from the water 
and immersed in the staining fluid for a sufficient 
time. The excess of stain is washed away in 
water, and if overstaining has occurred the organ- 
isms can be decolorized while still inclosed in the bags by adding a 
trace of HCl to the water. The bags are now cut open, the stained 
organisms transferred to a watch glass and mounted. Should they still 
be overstained they can be further decolorized in the manner stated. 
manner indicated, after which the bag is securely 
