102 A Physicist on Evolution. 



pollen-mass upon its back necessarily conies first into contact with 

 the viscid stigma," which takes up the pollen ; and this is how that 

 orchid is fertilized. Or take this other case of the Catasetum. " Bees 

 visit these flowers in order to gnaw the labellum ; on doing this they 

 inevitably touch a long, tapering, sensitive projection. This, when 

 touched, transmits a sensation or vibration to a certain membrane, 

 which is instantly ruptured, setting free a spring by which the 

 pollen-mass is shot forth like an arrow in the right direction, and 

 adheres by its viscid extremity to the back of the bee." In this 

 way the fertilizing pollen is spread abroad. 



It is the mind thus stored with the choicest materials of the 

 teleologist that rejects teleology, seeking to refer these wonders to 

 natural causes. They illustrate, according to him, the method of 

 nature, not the " technic " of a man-like artificer. The beauty of 

 flowers is due to natural selection. Those that distinguish them- 

 selves by vividly contrasting colours from the surrounding green 

 leaves are most readily seen, most frequently visited by insects, 

 most often fertilized, and hence most favoured by natural selection. 

 Coloured berries also readily attract the attention of birds and 

 beasts, which feed upon them, spread their manured seeds abroad, 

 thus giving trees and shrubs possessing such berries a greater 

 chance in the struggle for existence. 



With profound analytic and synthetic skill, Mr. Darwin inves- 

 tigates the cell-making instinct of the hive-bee. His method of 

 dealing with it is representative. He falls back from the more 

 perfectly to the less perfectly developed instinct — from the hive-bee 

 to the humble-bee, which uses its own cocoon as a comb, and to 

 classes of bees of intermediate skill, endeavouring to show how the 

 passage might be gradually made from the lowest to the highest. 

 The saving of wax is the most important point in the economy of 

 bees. Twelve to fifteen pounds of dry sugar are said to be needed 

 for the secretion of a single pound of wax. The quantities of nectar 

 necessary for the wax must therefore be vast ; and every improve- 

 ment of constructive instinct which results in the saving of wax is 

 a direct profit to the insect's life. The time that would otherwise 

 be devoted to the making of wax is now devoted to the gathering 

 and storing of honey for winter food. He passes from the humble- 

 bee with its rude cells, through the Melipona with its more artistic 

 cells, to the hive-bee with its astonishing architecture. The bees 

 place themselves at equal distances apart upon the wax, sweep and 

 excavate equal spheres round the selected points. The spheres 

 intersect, and the planes of intersection are built up with thin 

 laminae. Hexagonal cells are thus formed. This mode of treating 

 such questions is, as I have said, representative. He habitually 

 retires from the more perfect and complex, to the less perfect and 

 simple, and carries you with him through stages of perfecting, adds 



