352 IN STARRY REALMS. 



and cocoons, into warm parts of the nest, in order that 

 they may he quickly hatched." * 



Well may Darwin speak of the brain of an ant as one 

 of the most wondrous particles of matter in the world. 

 We are apt to think that it is impossible for so minute a 

 piece of matter to possess the necessary complexity re- 

 quired for the discharge of such elaborate functions. The 

 microscope will no doubt show some details in the ant's 

 brain, but these fall hopelessly short of revealing the 

 refinement which the ant's brain must really have. The 

 microscope is not adequate to show us the texture of 

 matter. It has been one of the greatest discoveries of 

 modern times to enable us to form some numerical esti- 

 mate of the exquisite delicacy of the fabric which we know 

 as inert matter. Water, or air, or iron may be divided 

 and subdivided, but the process cannot be carried on inde- 

 finitely. There is a well-defined limit. We are even able 

 to make some approximation to the number of molecules 

 in a given mass of matter. It has been estimated that the 

 number of atoms in a cubic inch of air may be approxi- 

 mately expressed by the number 3, followed by no fewer 

 than twenty ciphers. The brain of the ant doubtless contains 

 more atoms than an equal volume of air ; but even if we 

 suppose them to be the same, and if we take the size of an 

 ant's brain to be a little globe one- thousandth of an inch 

 in diameter, we are able to form some estimate of the 

 number of atoms it must contain. The number is to be 

 expressed by writing down 6, and following it by eleven 

 ciphers. We can imagine these atoms grouped in so many 

 various ways that even the complexity of the ant's brain 



* Darwin, "Descent of Man," p. 147. 



