CONSTITUTION AND DEVELOPMENT OF TERMITES. 250 
insects or nymphs, these eight, ten, or twenty will form a new 
colony, which slowly but surely will become as flourishing as 
the original stock. 
It follows, therefore, that the extirpation of these insects is 
excessively difficult in practice; and their entry into any 
situation where they can prove destructive must be prevented. 
This is the strategy to adopt against them, for when once they 
have gained admission there is no way of getting rid of 
them. 
The present work has no claim to be a complete monograph 
of the Termitidz, and merely furnishes materials for whomso- 
ever will undertake so large a task. It is confined, in short, 
to the discussion of certain fundamental points. 
Before concluding I must express my thanks to Dr. Calan- 
druccio, who has given me no little help in this research. 
Many observations, particularly those on Calotermes kept 
in tubes, have been made under my supervision by my pupil 
Dr. Sandias, and have afterwards been carefully verified by 
myself. 
Tur CoLony or CALOTERMES FLAVICOLLIS. 
1. Situation and Nest. 
As with all Termitide, the life of Calotermes is intimately 
connected with the vegetable kingdom, for it lives exclusively 
on woody matter. At Catania I have found it only in the 
stems or roots of living but partially decayed, and therefore, 
as a rule, old plants, and never in those of which the stem or 
tap-root measures less than one or two centimetres in thick- 
ness. But when once established in a stem or main root it 
can extend into decayed portions of the branches or side-roots, 
even if of lesser diameter. Though always absent in entirely 
sound plants, it can be found in partly decayed examples of 
many kinds,—of many, but not of all, for I have never met 
with it in lemon, orange, or Agave americana, &c. It is 
also relatively scarce in cactus (Opuntia), even though large 
portions of the plant are dead; but if present, it may infest 
