or THE glowworm (lampybis noctiluca). 63 



slime has become adherent to the body and is partially dried, the 

 creature seems to have the power of detaching it, by curling the 

 posterior part of the body round in every direction, and using the 

 apparatus in the manner of a hand or claw for that purpose. 



The Luminosity of the Larva. 



The luminosity exists at the very moment that the embryo is 

 escaping from the egg-shell and amnion. At that time a faint light 

 is given out from the ventral surface of the anal segment of the 

 being that is starting into active existence. I have repeatedly seen 

 light emitted from those parts on each side of the twelfth segment, 

 when the little creature has but the minute before been liberated, 

 and is still a feeble creeping body of a pale straw colour, and not 

 one line in length. Macaire also mentions the fact (Journal de 

 Physique, July 1821, torn, xciii.) of having seen the light in larvaB 

 that had just quitted the egg, and were of the size mentioned above. 

 I have found the light given out most vividly when the little body 

 has been suddenly disturbed or slightly compressed. 



I have noticed the light at this early period in all my specimens 

 reared in the closed glass tube, as well as in those produced from 

 eggs still attached to a tuft of grass-roots in the soil. Even at 

 this early period I have found that the little insect may be induced 

 to give out its light more brightly than usual, when it is placed in 

 a tin box, and agitated slightly by shaking this in a dark room. 

 The light then emitted resembles two very minute brilliant points, 

 the brightness of which is constantly varying and twinkling, like 

 stars of the smallest magnitude in the heavens. 



It is thus evident that the same influence that occasions the 

 perfect glowworm to shine with increased brightness, operates 

 equally in the very young larva. And as the light is given out by 

 the larva from its birth, there is reason to think that the luminosity 

 of the egg, at the later period of development of the embryo, is 

 not due to any luminous property of the yelk-tissue, but to the 

 special light-giving organs of the embryo. 



But although light has been observed at this early period of the 

 larva only by Macaire and myself, it has been long known that the 

 larva, at a later period of growth, emits light. This was noticed 

 by Swammerdam (Bibl. Nat. p. 124), and afterwards by Degeer 

 (Mem. de l'Acad. des Scien. Paris, torn. ii. p. 261), and since by 

 Schmidt, Macaire and Todd ; and Burmeister has shown that the 

 larva of L. splendidula is also luminous. 



