DISEASES OF THE ROSE. 205 



appearance, I should state, that it had been like summer weather for 15 days, 

 which was probably the cause of the difference. In 1844, it was on the 20th of 

 April. 



The insect makes its puncture at the arm-pit of the leaves or bracts, growing 

 on the sprouts which bear the flower. This support or stalk is more juicy and 

 larger than that which bears leaves alone — and is thus preferred by the insect, 

 although the leaf stalk is by no means exempted. Thence it digs a passage, 

 uses the tender pulp for its food, in the same way with many other insects. 



This false caterpillar, as naturalists term it (they regarding as the true those 

 alone which become butterflies, having five or six eyes on each side of the head, 

 etc.), grows in length for about 12 or 15 days. Imperceptible at first, it finally 

 attains from three to six lines in length, by a-half line or more in thickness. It 

 eventually assumes the green color of the leaves of the rose-bush, and forms one 

 of those natural harmonies so eloquently described by Bernardin de Saint Pierre. 

 Its body is smooth, nearly transparent, cylindrical ; its head is globular and shin- 

 ing, with an eye on each side, resembling a little spot ; its mouth, crosswise, red- 

 dish, and more deeply colored at the corners. The under side of the body presents 

 six fore-feet, and next to these nine wrinkles provided each with two nipples, 

 which appear to be additional or hind-feet. If this animal is viewed in an Artifi- 

 cial light, its-great intestine is. seen, the whole length of the body, like a colored 

 line. Two worms sometimes get into the same passage of the stem. This hap- 

 pens when two saw-flies have attacked the support at different points, and meet 

 in the same passage. They become poor and soon die ; but it is a rare occm'rence. 

 At other times, the larva perishes when there is but one, on account of its inability 

 to escape from the passage, by reason of the toughness of the plant, or the thick- 

 ness the wood has attained since its entrance. This may, perhaps, be one cause 

 of the decay of rose-plants. The ordinary duration of its stay is from 12 to 15 

 days. In that time it lives protected from the heat of the sun, or from the cold, 

 very much at ease in a pliable asylum, whose tender pulp serves it for food. 



This passage is from eighteen lines to two inches long. Its inside is smooth 

 and moulded, as it were, upon the form of the false caterpillar, in such a manner 

 that it cannot turn round in it. Upon pressing the peduncles between the fingers, 

 it will be perceived that they are fistular, and that their volume is, in fact, much 

 greater than those which do not shelter these destructive insects. 



The larva carries away the remaining excrement by means of the entrance- 

 opening, to which it ascends backward, as it cannot turn round in the gallery. 

 It consists of small, slightly curved cylinders. The insect lays it in a little heap, 

 reddish, at first, but afterward nearly blackish, which is perceptible to the naked 

 eye, and reveals to the somewhat careful observer this enemy of the most beauti- 

 ful blossoms. As it increases in size, the last excrements force out the old, and 

 thus the little heap becomes visible, as just stated. 



The hole by which the worms escape, is in proportion to their size. It is 

 usually at the lower part of the passage ; but is sometimes found higher up, and 

 sometimes even midway, probably because the animal found the stem thicker, 

 harder and more firm at the bottom, than at the place it finally selected for that 

 purpose. This hole is evidence of its dislodgment, or at least that there are not 

 two inside, as sometimes happens ; sometimes the passage is very short, because 

 the animal was so poor that it could not dig farther. 



It makes egress, as I have described, from the passage where it was nourished 

 and grew j but, with a single exception, I have never yet been able to catch it in 



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