264 
HISTORY OF BRITISH CRUSTACEA. 
and to mount up as along a canals carrying in the current 
the particles destined for its food towards the mouth. It 
seems to be constantly, when in this position, employed in 
swallowing and digesting its food, its masticatory organs 
being in perpetual motion.”* 
The Tairy Shrimp seems to live on dead animal or vege- 
table matter. 
Dr. Shaw, who has given a history of it,+ tells us that 
the females deposit their eggs in March and April, without 
any settled order, and perfectly loose in the water. They 
appear to the naked eye like very minute globules, “ scarce, 
if at all, exceeding in size the particles of the farina in a 
mallow ; and what makes this comparison the more just is, 
that each ovum, when magnified, is extremely like one of 
the globules of farina in that plant, for it is thickly beset on 
every side with sharp spines.” These, Dr. Shaw supposes, 
may probably be intended to assist in causing them to 
adhere to the substances on which they fall when extruded, 
as well as defend them from the smaller water-insects. 
* Baird, Brit. Entomostraca, pp. 47, 48. 
f Linnean Transactions, vol. i. pp. 103, 110. 
