120 FRUIT CULTURE UNDER GLASS. 



other causes. A female which had produced six eggs at eight 

 o'clock A.M. on the 20th of August, had fifteen on the 21st at four 

 P.M. that is, she laid nine in thirty-two hours. Other females 

 lay one, two, or three eggs in twenty-four hours. The maximum 

 quantity is thirty in five days. The eggs are generally piled up 

 near the mother without any apparent order, but she sometimes 

 changes her position so as to scatter them all around her. They 

 have a smooth surface, and adhere lightly to each other by means 

 of a slimy matter which attaches to them. 



" Hatching takes place through an irregular and often lateral 

 rent in the egg, the empty and crumpled membrane being found 

 among the other eggs in different stages of hatching. 



" During the first period of their active life two, three, four, 

 or five days, as the case may be the insects are in an erratic 

 state. They creep about as if they were seeking for a favourable 

 situation. Their movements are more rapid than those of adults. 

 They appear to inspect, as it were, with their antennae, the sur- 

 face they travel over. The movements of the antennae are 

 generally alternative, and, if the comparison may be pardoned, 

 are not unlike the two sticks of a blind man, which he uses to 

 explore the ground he is about to tread. 



" After a few days of this errant life, the young insects seem to 

 fix upon a spot to settle in. Most frequently this is a fissure in 

 the bark of a vine, where their suckers can be easily plunged into 

 the cellular tissue, full of saccharine matter. If you make a 

 fresh wound on the root by cutting off a little piece of the bark, 

 you may see the pucerons range themselves in rows around the 

 wound, and, once fixed, they apply to the root their antennae, 

 which appear like two small divergent horns. At this period of 

 their life, about the 13th or 14th day after their birth, they are 

 more or less sedentary ; but they change their places if a new 

 wound is made on the root, which promises a fresh supply of 

 food. . 



" What sense is this which directs these subterraneous pucerons 

 towards the place which is most suitable for them ? It cannot 

 be sight, as their eyes are merely coloured spots, and they creep 

 as if they were blind. It cannot be hearing, because they seek 

 no prey but a vegetable tissue. It is probably the sense of 

 smelling ; and one may well ask if the nuclei which appear 

 enshrined in the last articulations of the antennae are not the 

 organs of this function, the seat of which has been so much dis- 



