178 GEOMETERS. 



which we saw progressing in regular " rank and file " across 

 one of the smooth green areas of our city. Most of the social 

 caterpillars, whilst occupying a common abode, are accustomed 

 to move in a certain degree of professional 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 England. 



The Tumblers and Posture-masters, whom we have aescribea 

 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 

 accomplish every step by alternately stretching out and looping 

 up their bodies in the form of a Greek H. They are no less 

 remarkable for the singular positions which their extraordinary 

 muscular power enables them to assume, when quiescent. 

 Attached to a branch by the hinder legs, they will remain, for 

 hours together, stiff and straight, stretched out at an angle 

 from it, or bent into some contorted curve. Of this descrip- 

 tion are the walking-branch caterpillars, elsewhere noted. 1 



After these, some of the most idle of our city's population, 

 we took notice of the most laborious the occupiers of subter- 

 ranean dwellings in its lowest quarter. Now, looking round 

 the oak tree for their insect representatives, we presently discern 

 them., in a dingy multitude of laborious ants bearing their 

 bulky burthens, and issuing from their dark abodes, excavated 

 in the trunk or root. These are Jet Ants, or Emmets black 

 and shining as well-fed negroes and without whip, or master, 

 1 Vignette. 



