50 ME. NEWPORT ON THE NATURAL HISTORY 



out a faint light, but after immersion for an hour or two they 

 ceased to shine. "When the ova and ovaries were removed, I found 

 that the segments gave out only a very faint light, although the 

 insect was still living, and light continued to be given out from 

 them for several hours, but very faintly. It was thus evident to 

 me that the ova which are within the ovarium certainly do not 

 emit light before deposition, but merely transmit that of the seg- 

 ments beneath them ; but when the ova are deposited, I am 

 inclined to admit that a very slight luminosity is sometimes 

 apparent, though this is due rather to the fluid covering of the 

 egg than to the egg itself. 



The Development of the Emlryo. 



I have stated that some of the eggs deposited between the 22nd 

 and 25th of June were removed into a glass tube, still attached 

 to the roots of grass to which they had been affixed. This was 

 done in order that the eggs might not be affected too much by 

 warmth and dryness during examination, as when they are long 

 exposed, or have not sufficient moisture, they quickly dry up and 

 are destroyed. If, however, they are enclosed in a tube, and the 

 interior of the tube only very slightly moistened occasionally, then 

 the eggs become developed as in the natural haunts. I did not 

 observe the development of the young Lampyris within the eggs, 

 as opportunities were wanting for my so doing, but only watched 

 that of the egg itself, and the time of appearance of the young. The 

 tube with the eggs was placed in the same box and under the same 

 circumstances precisely as some of the same brood of eggs which 

 still remained attached to the roots of grass. In both these sets 

 I found that at about the 25th or 28th day after the eggs had 

 been deposited they were considerably enlarged,— a certain sign 

 that their development was in progress ; this increase was very 

 distinctly marked at this time, viz. about the middle of the period 

 of development of the embryo, in accordance with what I have 

 before and since observed in the development of other species of 

 insects and in other broods of eggs of the glowworm itself, as well 

 as in the Iulidce (Phil. Trans. 1841). 



On the 7th of August I had the satisfaction to find that the 

 eggs in the tube, which had been deposited between the 23rd and 

 25th of June, were producing their larva?. I had been prevented 

 during the interval from watching minutely the daily progress of 

 the eggs, and I am unable to detail the steps of the formation in 



