The Hexagonal Structure formed in Cooling Beesicax. 121 



tliird joint of antennse was gone in his tjpe ; in these three 

 female specimens it is tlie same colour as the preceding ones, 

 long and slender, its first annulation wide, the others tapering 

 off to a point. Walker's tjpe cannot be identified from 

 amongst the three females. 



N.B. — The name chri/sophilus was used by Macquart 

 (Hist. Nat. Dipt. i. p. 194) for an African species; since^ 

 however, chrysopMlus^ Walker, is differently derived, both 

 designations may be retained. 



Ilab. Australia. 



? Corizoneura erratica, ^ , Walker, List Dipt. pt. i. p. 189 

 (1848). 

 Tabanus erraticus, Walker, I. c. 



This was placed by Walker among the Tabam) but it is 

 distinctly a Pangomay Latr. ; the eyes apparently bare; it is 

 in very bad condition, the antennae broken off, one lying on 

 the face. 



Hah. North or north-west coast of Australia. 



The Pangonia corij'ungens, $ , Walker (List Dipt. pt. i. 

 p. 140), from Australia, type, is missing. 



The Pa?igonia lurida, ? , Walker, is not a Pangonia at all j 

 it belongs to the Tabaninas. 



[To be continued.] 



1 lb 



XIU. — The Hexagonal Structure naturally formed in Cooling 

 Beeswax, and its Influence on the Formation of the Cells of 

 Bees. By Chakles Dawson, F.G.S. &c , and S. A. 

 WOODHEAD, B.Sc, F.C.S., &c.. County Analyst, East 

 Sussex *. 



The hexagonal arrangement of the cells of bees has been 

 generally ascribed to a structural instinct. The object of 

 this paper is now to show that the form of the bee-cell is 

 chiefly influenced by a crystalline or pseudo-crystalline 

 hexagonal formation due to the cooling of the wax. 



While experimenting with waxes and resins, one of us 

 (Mr. Dawson) noticed that on cooling the mixture had a 

 tendency to arrange itself in hexagonal forms, from which 



* Communicated by tbe Authors, having been read at the Dover 

 Meeting of the T3ritish Association, 1899. 



