KOLLIKER, ON LAMPYRIS. 171 
produced when non-luminous individuals were exposed to the 
poisonous vapours in question. The luminous organs were 
in like manner destroyed by a powerful electric current, 
alcohol, ether, organic acids, &c. 
Of other injurious agents, many, at any rate, do not neces- 
sarily annihilate the luminous property for ever. ‘Thus 
animals which have been dried, are resuscitated when mois- 
tened with water, and exhibit luminosity ; and, in the same 
way, individuals benumbed by cold (0° to — 5°) are revived 
by the warmth of the hand. Moreover, I have succeeded in 
restoring the luminous property of entire insects, and of 
isolated organs, which had been deprived of it by a solution 
of salt containing 12 to 20 per cent.—that is to say, by the 
forcible abstraction of water, by immersing them again in 
water. There is thus no doubt that further experiments will 
show, that, in the case of these organs, pretty nearly the 
same phenomena of revivification take place as in the sper- 
matic filaments and nerve-fibres. 
Under favorable circumstances, the length of time during 
which the excitability of the luminous organs is maintained, 
and the light itself may be produced, is very considerable. 
In moist atmospheres, as well as in diluted solutions of 
salt, sugar, and albumen, the separated abdomen will often 
continue in a luminous condition for twenty-four to thirty- 
six hours. The greatest length of time during which I have 
noticed the luminosity to continue, viz., forty-nine hours, 
was in a moist atmosphere of oxygen. In water, that is to 
say, when the animal is moistened all over, the luminous 
property ceases to be manifested in a rather short time— 
usually in one to three hours. 
15. When insects moistened with a solution of salt were 
placed with the cephalic and caudal extremities on the 
cushions of Du Bois’s current apparatus, those in a luminous 
condition, and especially females, deflected the needle of the 
multiplier from 3° to 7°, the head at the same time appearing 
to be positive. This result, however, was not quite constant, 
and further experiments will be necessary before any further 
conclusions can be safely drawn from it. 
Non-luminous animals, even when they moved on the 
cushions, usually afforded, with my multiplier of 16,000 
turns, no indication whatever of a current, or, at most, did 
not deflect the needle more than 1° or 2’. 
16. I was very desirous of determining whether there was 
any difference of temperature between the luminous and non- 
luminous animals, but owing to the circumstance that the 
experiments were delayed till quite the close of the season in 
