298 AFFECTION OF INSECTS FOR THEIR YOUNG. 



pleasurable description ; and, like the affectionate father whose 

 love for his children sweetens the most painful labours, these 

 little insects are never more happy than when thus actively 

 engaged. " A bee," as Dr. Paley has well observed, " amongst 

 the flowers in spring (when it is occupied without intermis- 

 sion in collecting farina for its young or honey for its asso- 

 ciates), is one of the cheerfuUest objects that can be looked 

 upon. Its life appears to be all enjoyment — so busy and so 

 pleased." ^ 



Of the sources of exquisite gratification which every rural 

 walk will ojoen to you, while witnessing in the animals them- 

 selves those marks of affection for their unseen progeny of 

 which I have endeavoured to give you a slight sketch, it will 

 be none of the least fertile to examine the various and appro- 

 priate instruments with which insects have been furnished 

 for the effective execution of their labours. The young of 

 the saw-fly tribe (^Serrifera^) are destined to feed upon the 

 leaves of rose-trees and various other plants. Upon the 

 branches of these the parent fly deposits her eggs in cells sym- 

 metrically arranged ; and the instrument with which she 

 forms them is a saw, somewhat like ours but far more in- 

 genious and perfect, being toothed on each side, or rather 

 consisting of two distinct saws, with their backs (the teeth or 

 serratures of which are themselves often serrated, and the 

 exterior flat sides scored and toothed), which play alternately ; 

 and, while their vertical effect is that of a saw, act laterally 

 as a rasp. When by this alternate motion the incision, or 

 cell, is made, the two saws, receding from each other, conduct 

 the egg between them into it.^ The Cicada, so celebrated 

 by the poets of antiquity, which lays its eggs in dry wood, 

 requires a stronger instrument of a different construction. 

 Accordingly it is provided with an excellent double auger, 

 the sides of which play alternately and parallel to each other, 



1 Natural Theology, 497. 



2 Latreille denominates this tribe Securifera ; but as the tool of these insects 

 resembles a saw and not a hatchet, we have ventured to change it to Serrifera^ 

 which is more appropriate. 



^ Prof. Peck's Nat. Hist, of the Slug-worm, t. 12. f. 12 — 14. 



