CELL-MAKING INSTINCT 287 



As natural selection acts only by the accumulation of 

 slight modifications of structure or instinct, each profitable 

 to the individual under its conditions of life, it may reason- 

 ably be asked, how* a long and graduated succession of modi- 

 fied architectural instincts, all tending towards the present 

 perfect plan of construction, could have profited the progeni- 

 tors of the hive-bee? I think the answer is not difficult: 

 cells constructed like those of the bee or the wasp gain in 

 strength, and save much in labour and space, and in the ma- 

 terials of which they are constructed. With respect to the 

 formation of wax, it is known that bees are often hard 

 pressed to get sufficient nectar, and I am informed by Mr. 

 Tegetmeier that it has been experimentally proved that from 

 twelve to fifteen pounds of dry sugar are consumed by a 

 hive of bees for the secretion of a pound of wax; so that 

 a prodigious quantity of fluid nectar must be collected and 

 consumed by the bees in a hive for the secretion of the wax 

 necessary for the construction of their combs. Moreover, 

 many bees have to remain idle for many days during the 

 process of secretion. A large store of honey is indispensable 

 to support a large stock of bees during the winter; and the 

 security of the hive is known mainly to depend on a large 

 number of bees being supported. Hence the saving of wax 

 by largely saving honey and the time consumed in collect- 

 ing the honey must be an important element of success to 

 any family of bees. Of course the success of the species 

 may be dependent on the number of its enemies, or parasites, 

 or on quite distinct causes, and so be altogether independent 

 of the quantity of honey which the bees can collect. But 

 let us suppose that this latter circumstance determined, as 

 it probably often has determined, whether a bee allied to 

 our humble-bees could exist in large numbers in any coun- 

 try; and let us further suppose that the community lived 

 through the winter, and consequently required a store of 

 honey: there can in this case be no doubt that it would be 

 an advantage to our imaginary humble-bee, if a slight modi- 

 fiication in her instincts led her to make her waxen cells 

 near together, so as to intersect a little ; for a wall in com- 

 mon even to two adjoining cells would save some little labour 

 and wax. Hence it would continually be more and more 



