OF THE OLOWWOEM (LAMPYEIS NOCTILUCA). 71 



laws of organization, which I shall attempt to explain in connexion 

 with the anatomy of the insect. 



The form which the insect assumes as a nymph is that of a 

 semicircular body. 



The Imago. 



On the 16th of June, the temperature of the atmosphere being 

 then 73° Eahr., and it having been likewise at nearly the same 

 height during some preceding days, the three female specimens 

 threw off their nymph covering and assumed the Imago state: 

 their change was thus completed at this high temperature in seven 

 days, — a very marked instance of the influence of increased heat 

 in accelerating the metamorphosis. M. Maille found that his 

 insects -passed fifteen dags as the interval between the larval and 

 perfect state, namely seven days of quietude in assuming the form 

 of nymph, and eight full days in the nymph state (Bull, des Sc. 

 Nat. viii. 297). But some specimens which I reared from the 

 larvae in the summer preceding this, left the larva state about the 

 25th of May, and at a much lower temperature of the atmosphere 

 than those now observed. 



The pupa-covering is exceedingly thin and delicate ; and not 

 only during the pupa state, but immediately when they became 

 perfect insects, my specimens shone very brightly. The tegu- 

 ment thrown off by the larva on becoming a pupa is solid and of a 

 dark colour, but that of the pupa, shed on assuming the imago 

 state, is almost colourless, and very thin and transparent. 



The two male specimens, which assumed the nymph state at 

 the same time as the females, did not reach the imago condition 

 until the night of the 20th of June, and were thus eleven dags in 

 the state of nymphs, so that the females appear to become perfect 

 much earlier than the males. This fact is of importance with 

 regard both to the natural history and the relative anatomical 

 development of the two sexes. The female undergoes but little 

 change in her anatomy, and continues in a semilarval condition ; 

 consequently she is most early fitted for leaving the puparium, 

 and is ready to receive the male, whose life is very limited. 



Erom the individuals thus produced, I may simply state that 

 I succeeded in again observing the deposition of eggs and the 

 hatching of larvae. 



We are now prepared, by the consideration of the natural 

 history, to proceed to the description of the anatomy of the 

 glowworm, which will form the subject of a future paper. 



