WINKLES. 201 
the Winkle and the state of the atmosphere, and 
still more, the philosophy of the reason assigned 
for the habit. 
The plant-eating Gasteropoda are said to “lay 
their eggs merely enveloped in a mass of jelly, just 
firm enough to retain its form in the water, and 
which, deposited on the fronds of sea-weed, or on 
the surface of rocks and stones, adheres to them 
with tenacity. The form of the mass is roundish, 
oval, or oblong, and it may be more complex in 
some. ‘The ova are always immersed in the mass, 
which forms a common bed to the whole; but 
besides this, each egg (or at most three or four 
eggs) has its own proper globule of jelly, con- 
SPAWN OF PERIWINELE, 
(magnified). 
tained within a skin or pellicle of the greatest 
tenuity, and which isolates it from the rest.””* 
_ The accompanying figure, which is copied from 
Dr. Johnston, represents the mass of spawn laid 
* Johnston’s Introd. to Conch, 351. 
