104 Mr Brindley, The 'procession of Cnethocampa pinivorci. 
fly was endeavouring to avoid their points by keeping in the 
middle of the back. This was the only instance of the kind 
noticed. It was clear that the hairs of the larvae were sedulously 
avoided. Their defensive power against Tachinid attack has 
been emphasised by Weeks* in his description of oviposition in 
larvae of Datana. Fabre omits reference to oviposition in 
C. pinivora (possibly his families being kept under glass were 
preserved from this attack), but devotes a chapter - ]" to the 
urticating properties of the hairs and states that their toxic 
power is greatest after the final ecdysis, which is apparently 
the second, as he merely mentions that the larva “ a trois 
costumes.” He figures, as does also Ratzeburg, the hairs as armed 
with numerous short teeth and states that the urticating secretion 
passes along the hairs from cutaneous glands. He also describes 
how his face and e} 7 elids were much inflamed after a morning’s 
handling of the final instar of the larvae, and that very great 
irritation is produced by rubbing the skin with a concentrated 
ethereal extract of the larval epidermis. Reaumur]; describes 
similar experiences in the case of G. processioned, and that he 
also suffered from handling larvae of G. pinivora. Mr H. Scott, 
Trinity College, informs me that in Algeria he has heard of much 
irritation of the skin in the case of an Arab who had been 
occupied in clearing a piece of ground of companies of G. pinivora 
or some closely allied form. In the case of the Cap Ferret pro- 
cession, the larvae being on their way to burrow, the toxic power 
of the hairs would, according to Fabre, be at its greatest, and it 
was quite obvious that they were dreaded by the Tachinids, but 
neither of the observers noticed any irritation after handling the 
larvae and bringing the eyes very near them. Very possibly, 
however, the toxic effect on the human skin is often not great in 
the open air, and would be noticeable only after longer contact with 
the larvae than in the present instance. Reaumur and Fabre 
give very interesting accounts of the “ simples ” they employed 
for relief from the irritation, the former finding parsley and the 
latter purslane the most effective remedy. 
The pine woods of Cap Ferret are easily reached by steamer 
from Arcachon several times a day and anyone who would devote 
a few days in the last two weeks of March to observations on the 
“ processionnaire du pin ” could do much towards filling the many 
gaps in our knowledge of it. I am indebted to Dr David Sharp 
for much kind advice in compiling these notes, especially as 
regards nomenclature and the literature of the subject. 
* “Method of oviposition of Tachina,” Entom. Amer. hi. 1888, p. 126. 
f loc. cit. p. 378. 
X loc. cit. p. 191. 
