COLLECTED OBSERVATIONS ON BRITISH SAWFLIES. 153 



of a minute Bio|)hagan being found on lEschnn viatica; and 

 Boudier lias discovered one that attacks tiie ant-lion in his 

 pitfall. This appears the most extraordinary instance of all. 

 The ant-lion constructs its pitfall for the sole purpose of 

 entrapping wandering and unwary flies that may chance to 

 venture too near the brink of the treaclierous precipice 

 prepared for their destruction : and here we see a powerless 

 insect boldly bearding the lion in his den ; and by the 

 insidious process of puncturing and depositing an e^^^^ that 

 will hatch within his body and produce a grub that will, by 

 slow degrees, consume his living flesh, avenging a whole 

 legion of flies which have fallen victims to his rapacity. 

 This is the most remarkable instance of all ; and here I will 

 draw the curtain over the harrowing scene. 



Still another feature must be added to this sad story, that 

 of eggs and egg-setting. Many of these Biophaga are so 

 minute that they are born and pass through the state of egg, 

 caterpillar, chrysalis, and imago, within the egg of a butterfly 

 or moth. I have been told that hundreds of these minute 

 creatures have been seen to issue from a single egg. Perhaps 

 it was in reference to these wonders that Cowper wrote : — 



" The sbapelj' limb aud lubricated joint 

 Witliin the small dimensions of a point, 

 Muscle and nerve miraculously spun 

 His mighty work, who speaks and it is done." 



4. The Phytophaga, which in the larval state feed entirely 

 on plants. The families are Tenlhredinida, Xyelidce, Siricidee, 

 and Cynipidce. Since it is compulsory that I should enter 

 more fully into the details of this order in a future portion of 

 this paper, I will not introduce them here. It is quite 

 certain that as our philosophical knowledge of the Hyme- 

 noplera progresses, many, perhaps all, of the groups which I 

 have called families will take the rank of natural orders. 



Although the characters by which this plant-eating tribe 

 seem so trenchant as to admit of neither difficulty nor 

 confusion, yet we shall see that it is so comprehensive as to 

 require subdivision within its own compass. Thus some may 

 be denominated Phyllopliaga, or leaf-eaters, from their larvae 

 eating the leaves only ; others, Myeloph/iga, from a similar 

 preference for the pith ; a third order, Xylop/taga, devour the 

 solid wood ; and a fourth have the singular economy of 

 setting up a diseased action locally in the plant, and eat 

 nothing but the abnormal productions which their attack has 

 occasioned, — these are the Nosophaga, or Cynipites. To the 



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