SUSPENSION OF PUP^. 273 



sails, usually steals away from the plant on which it 

 has been feeding, to find some secluded corner where 

 it may undergo its transformation unmolested; as if 

 it were previously aware that it would no longer be 

 able to escape from its enemies. Those which we 

 shall first notice climb up the highest objects near 

 them, such as walls, gates, palings, and trees, under 

 the projections of which they think they may begin 

 their operations in safety. Thus we once found a ca- 

 terpillar of the small tortoise-shell butterfly upon the 

 branch of a fir-tree, in Epping Forest, from ten to 

 twelve feet above its native patch of nettles below; 

 and we have seen the cabbage butterfly under the 

 lintel of a window on the third story. * 



Having thus selected a safe spot, the caterpillar 

 begins, in order to attach itself securely, to weave a 

 mooring of silk, the structure of which is well worthy 

 of notice. The threads of which this is composed are 

 so fine, that they are not easily distinguished; and 

 we recollect being not a little astonished at seeing a 

 chrysalis of the admirable butterfly ( Vanessa JLia- 

 lanta) hanging within an inverted glass tumbler, 

 where we had confined it, the silk being transparent, 

 and all but invisible. It is necessary, therefore, in 

 order to see it distinctly, to confine the caterpillars 

 within a black box or other vessel. The silk threads 

 are not drawn tight along, so as to be parallel with 

 the surface, but are formed into a sort of projecting 

 button, the caterpillar, for this .purpose, alternately 

 raising and depressing its head over the spot so as to 

 draw out the threads, in the same way as a tambour- 

 ing needle is worked in making a dot upon muslin: 

 the base is accordingly made the broadest part, and 

 the centre the most projecting, for a reason which will 

 immediately appear. 



When it has finished this little button of silk 



* J. R. 



