304 DIPTEKA. 
regardless of their usual tranquil ha- 
bits, they leap, and bound, or dash 
their heads against the trees ; and this 
state of extreme anguish and irritability 
returns every time the larvae change their 
places. 
Lucy, The poor sheep, then, must 
constantly suffer, for I suppose their per- 
secutors often move ? 
Mother, The larvae have tw^o barbed 
claws, by which they probably stick fast 
in one spot till all the food within reach 
is consumed. When ready to become 
nymphs, they let themselves drop from 
the sheep's nose to the ground, and ga 
through their changes in the same man- 
ner as the first species which I described.. 
There are twelve species of this fly, but 
the last which I shall mention is the 
osstrus tarandi^'^, the implacable enemy 
of the rein-deer, into whose flesh, like the 
oestrus bovis, it introduces its eggs. The 
* From Cervus Tarandus, the rein deer. 
