220 SPECIAL INSTINCTS. [Chap VIIL 



the instinct — always supposing each modification to be of use to the 

 epeciea —until an ant was formed as abjectly dependent on its 

 slaves us is the Formica rufescens. 



Cell-making instinct of the Hive-Bee. — I will not here enter on 

 minute details on this subject, but will merely give an outline o\ 

 the conclusions at which I have arrived. He must be a dull man 

 who can examine the exquisite structure of a comb, so beautifully 

 adapted to its end, without enthusiastic admiration. We hear from 

 mathematicians that bees have practically solved a recondite pro- 

 blem, and have made their cells of the proper shape to hold the 

 greatest possible amount of honey, with the least possible con- 

 sumption of precious wax in their construction. It has been re- 

 marked that a skilful workman with fitting tools and measures, 

 would find it very difficult to make cells of wax of the true form, 

 though this is effected by a crowd of bees working in a dark hive. 

 Granting whatever instincts you please, it seems at first quite 

 inconceivable how they can make all the necessary angles and 

 planes, or even perceive when they are correctly made. But the 

 difficulty is not nearly so great as it at first appears : all this 

 beautiful work can be shown, I think, to follow from a few simple 

 instincts. 



I was led to investigate this subject by Mr. Waterhouse, who has 

 shown that the form of the cell stands in close relation to the 

 presence of adjoining cells ; and the following view may, perhaps, 

 be considered only as a modification of his theory. Let us look 

 to the great principle of gradation, and see whether Nature does 

 not reveal to us her method of work. At one end of a short series 

 we have humble-bees, which use their old cocoons to hold honey, 

 sometimes adding to them short tubes of wax, and likewise making 

 separate and very irregular rounded cells of wax. At the other end 

 of the series w T e have the cells of the hive-bee, placed in a double 

 layer: each cell, as is well known, is an hexagonal prism, with 

 the basal edges of its six sides bevelled so as to join an inverted 

 pyramid, of three rhombs. These rhombs have certain angles, and 

 the three which form the pyramidal base of a single cell on one 

 side of the comb enter into the composition of the bases of three 

 adjoining cells on the opposite side. In the series between the 

 extreme perfection of the cells of the hive-bee and the simplicity 

 of those of the hnmble-bee we have the cells of the Mexican 

 Melipona domestica. carefully described and figured by Pierre Huber. 

 The Melipona itself is intermediate in structure between the hive 

 and humble bee, but more nearly related to the latter ; it forms a 

 nearly regular waxen comb of cylindrical cells, in which the young 



