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EMERGENCE OF MSCHNA GRANDIS. 

 By H. T. Dobson, F.E.S. 



My friend, Mr. W. J. Lucas, the author of * British Dragon- 

 flies,' having asked me to take charge of two nymphs of Mschna 

 grandis diuxinghis absence from home, I gladly accepted his offer, 

 thinking that I might learn something of the habits of this species ; 

 a desire which, I am pleased to say, has been fully realized. 



One nymph died in a few days, but the other I fed daily with 

 a worm for several weeks, till at last it refused food, and then 

 rested for several days just under the surface of the water on a 

 lily leaf. After this period of rest, it crawled up a thin green 

 stick till it had reached several inches above the water ; this 

 was done on the morning of August 26th, The insect having 

 surveyed this new aspect of life seemed somewhat alarmed, and 

 descended into the water again, resting on the under surface of 

 the lily-leaf. In this position I observed it several times during 

 the following day ; however, at 8 p.m., the nymph left the water 

 and ascended a green twig until it had risen about six inches 

 above the water. 



From that moment it seemed to commence the real work for 

 its future life. However, before I begin a description of the 

 emergence, it would be as well to observe that there was no day- 

 light at 8 p.m. on August 27th, and that the only artificial light 

 I had in the room at the time was one candle, a light which was. 

 not increased until the nymph-case was broken. 



At five minutes past eight the upper part of the insect was 

 dry, and it was quite obvious that great internal exertions were 

 being made. Two minutes later I observed that the head of the 

 embryo dragonfly had been drawn through the neck and below 

 the head of the nymph. In another one and a half minutes, or, 

 to be exact, at eight and a half minutes past eight, the skin of 

 the nymph below its head had so swollen that it split, when 

 instantly emerged the head of the fly. In twenty seconds the 

 legs were partly visible, and the work of drawing them out of 

 their old case continued till all were free by ten past eight. The 

 next moment the released portion of the insect fell down, the 

 head facing the water. A rest of twenty-five seconds followed, 

 after which the struggle for freedom continued, so much so that 

 by fourteen minutes past eight, seven segments were outside the 

 case. During the efforts that were made while the insect was 

 head downwards, I observed that the wing-cases of the nymph 

 had been placed across the twig that it hung upon, so as to form 

 a lever for the new-born fly to pull against. By fifteen minutes 

 past eight the only movements observable were in the legs, which 

 were quivering ; then the first pair were placed round its head. 



For the next seven minutes it remained motionless, and thus 

 gave me time to take a sketch of its position. At thirty-two 



