LOCAL DISTRIBUTION OF INSECTS. 519 



to subside, you may generally reap a plentiful harvest of 

 various kinds. 



You see, now, how varied is the scenery to which the 

 diversion of the Entomologist introduces him ; that he 

 is never out of his way : whether on hill or in valley ; on 

 upland or plain; on the heath or in the forest; on the 

 land or on the water ; in the heart of a country or on 

 its shores ; still his game is within his reach. But in 

 order to enable him to pursue it with greater prospect of 

 success, he must recollect that not only is every face of 

 the country to be explored, but both the plants and the 

 animals that it produces ; and that he must not turn with 

 disgust from even the carcase or the excrement of the 

 latter. As numerous species of herbivorous insects feed 

 only on one kind of plant, the Entomologist, when he 

 discovers a scarce one, should examine it with the hope 

 of finding upon it a scarce insect. Sometimes it happens 

 that only a single opportunity occurs in a man's life of 

 seeing certain plants growing wild : such opportunities 

 should never be neglected. Some insects also inhabit a 

 plant in one district or season, and not in another. Thus 

 the most beautiful of the Apions, A. Limonii a , though the 

 plant it feeds upon usually abounds near the sea, I have 

 discovered only on the northern coast of Norfolk; and an- 

 other scarcely less beautiful, but more minute (A. As- 

 tragali b ), though I have sought for it year after year, As- 

 tragalus glyciphyllus being abundant near me, I never 

 found but once. The blossoms of plants as well as the 

 leaves must be inspected. In those of the rose, the Ce- 

 tonia aurata is often taken c ; and in the bells of the dif- 



* Linn. Trans, ix. 78-. t. i./. 20. b Ibid. 55. t. If. 12. 



e This insect does not, I believe, eat the petals of the rose, but 



