GEOMETERS. 103 



move in a certain degree of processional order ; but the species 

 more especially celebrated for the soldier-like regularity of 

 their marchings, which are performed in parallel files, from one 

 to six deep, and always headed by a single leader, is the "Oak 

 processionary," a native of France, but not, we believe, of Eng- 

 land. The same military mode of progression is, however, 

 exemplified with scarcely less exactness, by several of our own 

 caterpillars, when in broods recently hatched, those, amongst 

 others, of the "Gold-tail" and "Buff-tip" moths, of whom 

 more in another place. A company of the latter,* when just 

 embodied (from the egg), and taking the field on the " green 

 area " of an oak leaf, are accustomed to march slowly over it 

 in even files, and foraging as they march to mark their pro- 

 gress, by leaving all behind them brown and arid, whilst all 

 before them is fresh and verdant. Though, from the size of 

 these Lilliputian troops, the colour of their uniforms is not 

 very distinguishable, a close observer may readily discern that 

 they are black and yellow. 



. The Tumblers and Posture-masters, whom we have described 

 in the exhibition of their wonderful performances in the 

 branching streets of our leaf-embowered city, belong to another 

 and very peculiar tribe of Moth Caterpillars. From their 

 singular mode of progression wherein they seem, as it were, 

 to measure the ground over which they pass they are called 

 "Measurers and Geometers" also, " Loopers," because they 



* Vignette. 



