1890.] 149 



April 5tli that the mystery was unravelled, and I saw semipurpurella 

 in the act of laying an egg. She had selected a rather forward bush 

 with the leaves already partially protruding. Her first step was to 

 examine carefully with her maxillary palpi, which looked in their 

 movements like a pair of delicate legs, the opened bud, and having 

 found it to her liking, she folded up her palpi, and took up a position 

 lengthways upon the exposed part of the leaf, curved round her ab- 

 domen and inserted its points between the folds ; a series of quick 

 thrusting or rocking movements with short intervals of rest took place, 

 and then the abdomen was gently withdrawn. She then travelled up 

 the twig, using her palpi incessantly, to the next bud, which she ex- 

 amined carefully as before, and again went through the same process ; 

 and thus she visited bud after bud on the twig, making but a single 

 laying in each. When the leaves were examined at home it was seen 

 that a small incision had been made in the under-side, which led to a 

 rather deep oval chamber or pocket, at the bottom of which the egg 

 lay. About the same time, and quite independently. Dr. Chapman 

 made a similar discovery in connection with purpurella. This species 

 usually sits across the leaf, and does not insert her abdomen between 

 the folds, but pierces the leaf on the edge of one of the lateral ribs. 

 Her pocket too is broader and shallower, and the three eggs which it 

 usually contains are placed side by side. 



When I first saw semipm'purella at work the weather was warm, 

 and she took about 2\ minutes to cut the pocket and lay her egg ; 

 but afterwards, in colder weather, the process occupied more than four 

 minutes. Unimaculella I have timed at a little over nine minutes, but 

 the weather was cold, and probably under favourable circumstances 

 she would be considerably quicker. I have not succeeded in watching 

 out purpurell a, and all I can say is that in cold weather she exceeds 

 fifteen minutes, but how much I do not know. This is in strong con- 

 trast to Incurvaria muscalella, another insect having the same habit, 

 which Dr. Chapman tells me cuts her pocket in the under-side of a 

 sloe leaf in from ten to fifteen seconds. 



The egg is about twice as long as broad, cylindrical, with rounded 

 ends, and with a white delicate shell, which yields readily to pressure. 

 Placed at the bottom of the pocket, there is at first ample space all 

 round it, but it steadily increases in size till it fills and fairly distends 

 the lower part of the pocket, but never quite reaches to the top. In 

 purpurella the eggs so press on each other in their growth that all 

 symmetry is lost. For the following measurements I am indebted to 



