594 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Of the thirteen pairs of large cells at the hinder end of the heart, 

 the six posterior pairs, and probably the portion of the heart betweon 

 them, fall victims to the voracity of the granular cells ; but the seven 

 anterior pairs persist. Prof. Kowalevsky draws attention finally to 

 the important shifting of tho heart from its deep position between the 

 tracheal stems in the larval, to its subsequent superficial position just 

 below the external epithelium. 



Structure of the Honey-Bee's Cell.*— Ilerr K. Miillenhoff reports 

 the results of his studies as to the influences resulting in the formation 

 of the honey-bee's cell. Extending the old observation as to tho 

 optimum exhibited by the form of the cell, he shows how its length is 

 also in perfect accord with the best solution of the bee's problem. 

 As to mechanical explanation, he extends Buffon's experiment with 

 the boiled bottled peas swollen into hexagonal form by mutual 

 pressure, by showing that the general resultant figures are really 

 rhombododecahedra, while those at the sides exhibit the exact form of 

 the bee's cell. After referring to Darwin's, for the most part topo- 

 logical attempt at solution, he directs attention to the necessity of 

 considering the nature of the component substance, the behaviour of 

 the bees, and the exact nature of the mechanical forces at work. This 

 he has elsewhere discussed in detail. f 



He emphasizes the perfectly plastic character of the wax at tho 

 temperature of comb-building (27 D -37° C), and distinguishes three 

 different phases in the process : — (1) The formation of Maraldi's 

 pyramids and short prisms, (2) the increase of the prisms to their 

 full length, (3) the filling and closure of the cells. Describing the 

 beginning of tho process, he shows how the simple contractility of 

 the material effects the disposition of the wax into small pellicles of 

 equal strength, the perfect squaring of the walls, and the formation 

 of surface angles of 120°. In describing the successive stages, he 

 lays special stress on the variations which must follow the changes of 

 temperature and the continued plasticity of the cell, which is con- 

 tinually tending to acquire smaller surface and stronger walls. The 

 cells behave mutually like soap-bubbles. Maraldi's pyramids are 

 literally Plateau's equilibrium figures— with the smallest surface 

 within given limits, and the whole cells are isoperimetric figures — 

 with smallest surface for given content. In short, not to any artistic 

 dexterity on the part of the bee, nor to any direct effect of its body- 

 form, but to " statical pressure according to the laws of equilibrium " 

 is the beautiful result to be referred. 



Storing and Preservation of Honey .% — Herr K. Miillenhoff, 

 continuing his studies of bees, has investigated the behaviour of the 

 insect in gathering and storing the honey. He discusses the damping 

 and the compression of the pollen, the marvellous adroitness of the 

 bee in forcing its way into flowers, the careful avoidance of mixing 

 the kind of pollen during one gathering, the renewed salivating and 



* Arch. f. Anat. u. Physiol.— Physiol. Abtheil., 1886, pp. 371-5. 

 t Pfliiger's Arch. f. d. Gcsammt. Physiol., xxxii. (1883) pp. 589-618. 

 % Arch. f. Anat. u. Physiol.— Physiol. Abtheil., 1886. pp. 382-6. 



