48 MK. NEWPORT ON THE NATURAL HISTORY 



very long time when unimpregnated ; and if at tlie end of several 

 days impregnation has not oeenrred, the natural instinct of the 

 creature becomes markedly affected, precisely as I formerly pointed 

 out is the case with tlie female Meloe under similar circiunstances 

 (Linn. Trans, vol. xx. p. 302) . Her body becomes greatly distended 

 by the fully matured ova ■w'ithin her ; the light loses its brilliancy 

 and is less constantly exposed, and its colour is changed to a green- 

 ish hue, She wanders about, with evident distress, less rapidly, but 

 more constantly, and ultimately deposits her eggs at random on the 

 grass over which she travels, or even on the ground, one or two 

 at a time. A very slight mechanical stimulus of touch or pressure 

 on her body will then occasion her to extrude an egg, but never- 

 theless she is extremely tenacious of life, and lives on until very 

 many of her ova have been carelessly extruded and scattered. After 

 some time she dies. In one experiment made to ascertain the 

 length of time the glowworm may live unimpregnated, I found the 

 light given out Avith greater brilliancy on the second evening after 

 the glowworm had been in confinement ; with still greater on the 

 third and fourth, at which time the little prisoner was evidently 

 in great distress, alternately traversing the sides and bottom of 

 the box in which she was confined, then remaining stationary for 

 a few minutes and emitting her light with its utnaost vividness, — 

 it being at one moment very bright, and then slightly dimmed for 

 a few seconds, but only to be shed again at the next instant with 

 greater brilliancy. The insect was strongly attracted by the light, 

 first to the one side and then to the opposite ; and the sexual im- 

 pulse was manifested by the frequent protrusion of the vaginal 

 portion of the body. On the fifth evening the light had become 

 fainter ; and from this time to the tenth day, when the insect died, 

 the light continued to diminish in brilliancy, and became of a much 

 greener colom\ 



At the moment of the laying of the eggs, each is covered with a 

 very glutmous and adhesive matter, as I have found when an egg 

 has been extruded from the body beneath my eye under a lens. 

 They are affixed firmly by means of this matter to the small ex- 

 posed roots or the base of the stems of blades of grass, though not 

 in the ground as some have stated, but close to the surface ; so 

 that, without being covered by the soil, they are constantly retained 

 in a humid locality, and yet are freely submitted to the influence 

 of heat and air, — conditions which I have constantly found abso- 

 lutely necessary for their development. Some naturalists have 

 stated that they are usually deposited on moss ; but this condition, 



