Eoyal Microseo'pical Society. 245 



like organs of Cepbalopods, Echini, and certain insects. That there 

 is frequently a very close application of the tongue of the fly and a 

 seemingly -well-marked eifort of suction, will, I think, be readily 

 accorded by anyone who has experienced the sensation immediately 

 following the alighting of a fly upon his forehead. 



The weak point of this theory would seem to be its apparently 

 requiring for the development of the suctorial power a close pressure 

 of the so-called tongue on a tolerably flat surface, and as apparently 

 requiring us to overlook the evident power of the insect to absorb 

 fluids, such as milk and syrup, by some simple process of aspiration. 

 But even in the latter case it would be fair to assume that such 

 aspiration, where the tongue could be immersed in the fluid, might 

 obey the same laws as in the purely haustellate insects. These 

 speculations — and they are but speculations — may not be confirmed 

 by a more perfect knowledge which the future may open out to us ; 

 but they are based on most minute and careful dissections of one of 

 the most, interesting and beautiful of microscopic objects, and I have 

 only ventured on the theory in the belief that circumstances in a 

 great measure seemed to warrant it. 



