1832.] BOTANIC GARDEN, 81 
_ When we were at Bahia, an elater or beetle (Pyrophorus lu- 
minosus, Illig.) seemed the most common luminous insect. The 
light in this case was also rendered more brilliant by irritation. 
I amused myself one day by observing the springing powers of 
this insect, which have not, as it appears to me, been properly 
described.* The elater, when placed on its back and preparing 
to spring, moved its head and thorax backwards, so that the 
pectoral spine was drawn out, and rested on the edge of its 
sheath. The same backward movement being continued, the 
spine, by the full action of the muscles, was bent like a spring ; 
and the insect at this moment rested on the extremity of its head 
and wing-cases. The effort being suddenly relaxed, the head 
and thorax flew up, and in consequence, the base of the wing- 
cases struck the supporting surface with such force, that the 
insect by the reaction was jerked upwards to the height of one 
or two inches. The projecting points of the thorax, and the 
sheath of the spine, served to steady the whole body during the 
spring. In the descriptions which I have read, sufficient stress 
does not appear to have been laid on the elasticity of the*spine : 
so sudden a spring could not be the result of simple muscular 
contraction, without the aid of some mechanical contrivance. 
On several occasions I enjoyed some short but most pleasant 
excursions in the nefghbouring country. One day I went to 
the Botanic Garden, where many plants, well known for their 
great utility, might be seen growing. The leaves of the cam- 
phor, pepper, cinnamon, and clove trees were delightfully aro- 
matic; and the bread-fruit, the jaca, and the mango, vied with 
each other in the magnificence of their foliage. The landscape 
in the neighbourhood of Bahia almost takes its character from 
the two latter trees. Before seeing them, I had no idea that 
any trees could cast so black a shade on the ground. Both of 
them bear to the evergreen vegetation of these climates the same 
kind of relation which laurels and hollies in England do to the 
lighter green of the deciduous trees. It may be observed, that 
the houses within the tropics are surrounded by the most beau- 
tiful forms of vegetation, because many of them are at the same 
* Kirby’s Entomology, vol. ii, p. 317. 
