22 HUMAN BIOLOGY 



its origin to be due to some happy, but almost infinitely 

 improbable, combination of favorable conditions. There 

 are but three bodies in our system upon which life as we 

 know it could have the least chance of survival. If it is 

 present upon two of these three, it is reasonable to suppose 

 that, if favorable physical conditions exist elsewhere in the 

 universe, fife would stand a good chance of coming into being. 



Whether animal fife, and, still more, inteUigent fife, 

 exists on Mars is a harder question. With oxygen to breathe, 

 and vegetation to provide food, animal life might well 

 exist; and we can assign no reason why intelligence should 

 not have evolved. But to obtain evidence of the existence 

 of such life, if it exists, upon a planet which never comes 

 nearer than about 35,000,000 miles would be a hard matter. 

 As is well known, Lowell believed that he had secured such 

 evidence, and his arguments were of a thoroughly scientific 

 character and deserve careful consideration. Briefly stated, 

 they are as follows: 



The network formed by the canals, which run in great 

 circle courses across hundreds of miles of desert, suggests a 

 geometrical diagram far more than a map. Accepting 

 the belief that they are water-courses, or rather the fertile 

 land on each side of these, it is beyond the bounds of credulity 

 to suppose that a system such as is shown on Lowell's 

 drawings is the product of geological forces; it appears 

 obviously, indeed glaringly, artificial. Hence the "canals" 

 represent strips of irrigated land flanking artificial water- 

 courses, and weie laid out by intelhgent creatures of high 

 engineering skill. As the polar snows recede, the canals 

 darken (vegetation grows). This "quickening" of the 

 canals progresses steadily toward the equator and even 

 beyond, and, in some cases, half a Martian year later, 

 it has been seen to follow the same canal in the opposite 

 direction. Now water may flow down hill one way, but 

 not both ways; hence it is carried along some canals, at 

 least, by artificial means; it is pumped; and the inhabitants 

 who made the canals are still there to work them. Indeed 

 the orderly and world-wide character of the system indicates 

 a degree of racial organization superior to the present state 

 of mankind. 



