OF THE OAKS. 161 



for, notwithstanding the pressure was very greatly 

 reduced, the caterpillars were still capable of 

 ascending the phial in which they were enclosed: 

 it is probable, therefore, that some adhesive 

 matter, which, perhaps, is not liable to leave a 

 stain upon glass, may be secreted, in small 

 quantities, by the spurious legs of these larvae ; 

 and that they are thus, in opposition to the at- 

 traction of gravitation, enabled to climb up the 

 vertical sides of bodies with smooth and even 

 highly polished surfaces. A minute examination 

 of the structure of the false legs, under a power- 

 ful microscope, might possibly throw some light 

 on this curious subject, which, it must be ac- 

 knowledged, merits further investigation. 



I hope, at some future period, to have an 

 opportunity of resuming my researches respect- 

 ing this singular property of the prolegs of seve- 

 ral species of larvae. In the mean time, should 

 the foregoing imperfect attempt to solve this 

 difficult physiological problem, by directing the 

 attention of naturalists to the inquiry, induce a 

 single individual to engage in the undertaking, it 

 will not have been made in vain. 



The injury sustained by the oaks on this 

 occasion, was not limited to those which grow 

 in this particular district. I am well informed, 



X 



