26 



ME. T. WEST OK APPENDAGES 



the branch of natural history to which I am most addicted, and, 

 through a channel whereby I can address myself especially to my 

 brother ornithologists *, to enter into details which I should not 

 be warranted in inflicting upon this Society, from some of whose 

 members, however, I trust to receive that support in investigating 

 the generalities of the case which can alone secure to the project 

 even the smallest degree of success. 



On certain Appendages to the Feet of Insects subservient to 

 Holding or Climbing. By Tueeen "West, F.L.S. 



[Abstract of papers read March 21 and June 6, 1861.] 



The structures in the foot of the Fly having long occupied the 

 author's attention, he was induced, by the fact of their minuteness 

 and the difficulties attending satisfactory examination and reason- 

 ing thereon, to search amongst insects generally for examples of 

 analogous structures on a larger scale. "With this view many 

 examinations were made of such insects as could be procured ; and 

 whenever practicable, they were viewed in action in the live-box. 

 The importance of this was urged as the only way to obtain 

 correct ideas regarding structures which must be more or less soft 

 in order to fulfil their intended purposes, and which, therefore, are 

 generally found shrivelled and distorted in dried specimens 



The labours of other observers in the same field were first 

 mentioned, from which it appears that the way in which some 

 insects are enabled to suspend themselves or to walk freely against 

 gravity had been ascribed to causes which might conveniently be 

 classified as follows : — 



A. By the entire cushions (of flies) acting as suckers. 



B. By the hairs with which the under surface of these cushions 

 is furnished acting 



a. as minute hooks ; 



b. as suckers ; 



c. by adhesion through the emission of a viscid secretion from 



supposed glands in their expanded terminations ; 



d. as suckers, adhesion being assisted by the emission of a 



small quantity of fluid from such supposed glands. 



The author then gave the results of his own examinations, 

 stating that similar structures to those on the feet of flies were 

 present in many beetles, the largest being on the dilated anterior 

 1;irsi of the males amongst the Geodephagi or ground-beetles. 



* Sec 'The Jbis' tor 18G1, V \>. lfKM00. 



