: à . : eans t0 
_ Wholly or in part, to give out its light, using it as me 
















430 THE WEST INDIAN FIRE BEETLE. 
nerves. This fatty matter is of a chalky whiteness, : 
when spread upon a slip of glass and examined by the mier 
scope, gives the characteristic appearance of fat globules. 
When rubbed upon paper and warmed, it leaves a g 
stain; and when the whole mass is digested in sulphi 
ether, the fat is dissolved out, leaving branch-like masses 0 
nerves in great abundance, and also the tubes of the ai 
vessels. The mass of luminous matter upon the abdome 
is, as has been stated, many times greater than that upon th 
thorax, and is covered externally by a very delicate and flex- 
ible membrane, which forms the joint, and reaches con- 
pletely across the animal. Inside it has not so distinct 
boundary, the vessels of other portions of the body be 
continuous with it, the luminous matter still being quite | 
tinct. In the thorax, this same substance is: found | 
behind the two oval, convex, transparent membranes, of 
horny nature, being separated from it by a very thin trans- 
parent membrane, which acts as a special envelope, f 
also supplied with nerves and air-tubes, as in the abdominal 
portion. i 
It becomes very evident to any one who attentively exam- 
ines these insects while in a living and healthy state, | 
their luminous power depends, not upon chemical action, . 
does the air in our lungs during respiration, which action 
must go on entirely independent of any voluntary oe 
the part of the possessor, but that it is completely under ™ 
control of the animal, and is used by it for purposes ae 
render its exercise at times wholly needless. It is also @ 
dent that whatever arouses the nervous energy of the ani 
to full activity, causes a corresponding manifestation of ne 
nosity ; and, on the contrary, whenever the insect ai d 
in media which depress its vital powers, and act ae 
rectly or indirectly upon its nervous masses, then it ¢™ ? 
3 
$ i i $ rer. 
accomplish a desired end, as truly as its muscular ae 
earl 1 
In concluding this paper, already unnecessarily long: 
