A Hit-or-Miss Universe 



321 



is, therefore, well worth while; but they 

 face some formidable difficulties. Can 

 they eliminate from heredity and de- 

 velopment all plan and design, all 

 "vital principle," all guidance of an 

 intelligence? Can they reduce the im- 

 mensely complicated life processes to 

 reactions that are, in principle, as non- 

 mystical as the evaporation of a drop 

 of water in the sunshine, or the rising 

 of a batch of dough which contains 

 baking powder? In short, can all 

 actions of so-called living matter be 

 referred to those well-known properties 

 which characterize so-called dead mat- 

 ter? Is there no essential difference 

 between the world of living things and 

 the world of winds, rocks and waters? 



Of course, much more knowledge must 

 be gained before any of the questions 

 involved can be answered with con- 

 fidence. Dr. Loeb attempts only to 

 pick out a few typical problems and to 

 show that these can be explained on a 

 purely mechanical basis. If the mech- 

 anistic explanation proves adequate in 

 one place, he argues, is it not right to 

 suppose that it may not also hold good 

 in other places ? Even with this limited 

 scope, his argument is frequently open 

 to the criticism of passing by difficulties 

 that to the reader may seem fatal. 

 However, the object of this review is not 

 to criticise his statement of the case, 

 but merely to give a summary of that 

 statement. 



THE NATURE OF LIFE 



1. First of all, is there any essential 

 difference between living matter and 

 dead matter ? Life and death are daily 

 accepted as antithetical, and it is 

 generally supposed that there is some 

 mystical quality inherent in life, which 

 distinguishes it from the primal elements 

 that admittedly enter into its makeup — 

 from carbon, hydrogen, oxygen, iron, 

 lime, and so on. Inquiry into the pos- 

 sible origin of life may clear up this point. 



At present the perpetuation of living 

 matter depends priinarily on sugar, 

 without which life ordinarily cannot 

 exist. Sugar is not found in minerals, 

 but is manufactured by plants, by the 

 help of the red rays of sunlight, from 

 the carbon dioxide of the air. But if 



the first life came from sugar, where 

 did the sugar come from? This diffi- 

 culty was .surmounted a few years ago 

 when it was discovered that some bac- 

 teria live exclusively on minerals, and 

 can produce sugar directly from these 

 minerals. It is no longer impossible, 

 therefore, to conceive of organisms 

 which could have existed on this 

 planet at a time when it contained only 

 minerals, no living matter; and which 

 could from these minerals have manu- 

 factured the sugar which was necessary 

 for the manufacture of proteins and the 

 evolution of higher forms of life. 



The first life in this world was possibly 

 a plant similar to the modern blue- 

 green algae. Experiments have failed 

 to show that spontaneous generation 

 can occur ; the modern belief is that life 

 comes only from life. It is then not safe 

 to assume that this primordial, one- 

 celled plant sprang into existence on the 

 cooling globe, merely by chance, and 

 Dr. Loeb inclines to believe that it was 

 carried here from some other planet. 

 "May not life after all be eternal?" he 

 asks. If so, it is merely necessary to 

 assume that it is passed on occasionally 

 from one planet to another. It cannot 

 come with meteorites, for they are too 

 hot ; but Arrhenius has suggested another 

 means of transmission, based on the fact 

 that for particles below a certain size the 

 mechanical pressure produced by light 

 waves can overcome the attractive 

 force of gravitation. 



Bodies which according to Schwarz- 

 schild would undergo the strongest 

 influence of solar radiation must have 

 a diameter of 0.00016 mm., supposing 

 them to be spherical. The first question 

 is, therefore: Are there any living seeds 

 of such extraordinary minuteness ? The 

 reply of the botanist is that s])ores of 

 many bacteria have a size of 0.0003 or 

 0.0002 mm., and there are no doubt 

 much smaller germs which microscopes 

 fail to disclose. 



"We will, in the first instance, make 

 a rough calculation of what would hap- 

 pen if such an organism were detached 

 from the earth and pushed out into 

 space by the radiation pressure of our 

 sun. The organism would first of all 

 have to cross the orbit of Mars, then 



