326 TRANSFORMA TIONS OF INSECTS. 
the emission of a fragrant odour not unlike that of otto of 
roses. 
The exuberant vegetation of tropical countries can well afford 
to be checked by the ravages of insects, and some of the largest 
trees, which require much heat and damp for their growth, are 
more or less destroyed by some of the largest larvae which are 
known. Thus in Guiana there is an immense beetle called the 
Titan ( Titanus giganteus), whose larva gnaws and makes gal- 
leries in the largest trees, and its size almost appears to bear some 
relation to the magnitude of its food. Again, in India, there 
are beetles with long mandibles which make them look almost 
like stag beetles, but the antennae are enormously long and 
spined at each joint, and they have very large larvae. The larva 
of Acanthophorus serraticornis lives under the bark of large trees 
in the neighbourhood of Pondicherry. It does not come into 
the light, and, like many other wood-borers, it forms galleries 
within the wood, and finally makes a cocoon of enormous dimen- 
sions out of the vegetable tissue. The engraving exhibits the 
beetle upon the outside of a tree, the larva being under the bark, 
and a great cocoon in a kind of gallery. 
The mimosa trees in the West Indies suffer greatly from a 
beetle which is called Lamia amputator. The larva bores and 
excavates the branches and delicate saplings of the trees, and under- 
goes its metamorphosis in them. This mischief having been done, 
the coup de grace is given by the perfect insect, for the beetle has 
a fancy for gnawing round the branches in a circular line, so as 
to cut them off completely. An allied species ( Oncideres vomicosa ) 
does very much the same sort of thing. M. Houllet, now the 
head gardener of the tropical department of the Musee d’Histoire 
Naturelle in Paris, once lived in the environs of Rio Janeiro, and 
every night he heard the sound of falling branches of trees belong- 
ing to the Acacia lebbeck. He found on examination that these 
branches were sawn all round in a circular direction, but their 
central part, or pith, was not touched, so that the branches 
broke by their own weight or by the simple force of the wind. 
The mischief was put down to the evil dispositions of the slaves 
of the house, but M. Houllet discovered a beetle upon a branch 
which had been thus cut, and it soon became evident that this 
