THE HEATH FRITILLARY 
131 
Egg Laying. The eggs are laid in batches varying in number 
from about 70 to 200 or more in a batch. The complement 
of eggs laid by a single female amounts to between 300 and 
400. A female I kept under close observation deposited her 
eggs on an average of one every 30 seconds, and three batches 
were laid : 138, 86, 76—total, 300. Others laid larger batches 
containing many more eggs. The eggs are normally laid on 
the under surface of the leaves of Cow-wheat ( Melampyrum ' 
pratensc), which is the chief food plant. The larvae have 
been found feeding upon Foxglove and on Wood Sage. In 
captivity they will readily feed up to maturity on Narrow¬ 
leaved Plantain, upon which the eggs have 
been laid. I have reared large numbers 
solely upon Plantain, on which the larvae 
flourished. 
Egg. When first laid the egg is a pale 
greenish-pearl-white, very gradually deep¬ 
ening in colour until the third day, when it 
assumes a pale lemon-yellow tinge, chiefly 
in shadow. It is 0-51 mm. high, and is ovate 
in form, the base being slightly flattened. 
There are about twenty-six shallow longi¬ 
tudinal ribs and the surface is finely striated 
transversely. The egg stage lasts sixteen 
days. They are laid during July. 
Larva. The larva, upon hatching from the egg, eats a 
small hole in the crown through which it creeps ; it then 
remains on the batch of eggs for some time afterwards. It 
measures 13 mm. long. From the first, the larvae are 
gregarious, living in company under a web on the under 
surface of the leaves and feeding on the cuticle, leaving only 
a thin membrane. They feed in little parties and return to 
the company after each meal. 
They hibernate, after the third moult, in companies, varying 
from a few to several dozen, under a web covering. Some 
were found hibernating in curled-up dead leaves. Also after 
hibernation they may be found sheltering under dead leaves 
in close proximity to their food plants. 
When fully grown, after the sixth moult, and about 300 
days old, the larva measures from 22 mm. to 25 mm. long. 
The Heath Fritillary 
(under side of ab. 
shown on page 130). 
