434 



SCIENCE. 



[N. S. Vol. XX. No. 509. 



While these particular operations are in 

 progress countless hoards of bacteria of 

 various kinds are each exercising their nat- 

 ural functions in the role of destroyers or 

 helpers, as the case may be. Surely we 

 may think of the soil as a factory full of 

 busy workers, causing incessant changes 

 and modifications, rather than as a simple 

 storehouse of accumulated riches. 



The prosperity of peoples depends upon 

 other factors than the fertility of the soil 

 on which their homes are made, but those 

 countries which are naturally most fertile 

 furnish man more easily and more abun- 

 dantly those things which may be used by 

 him in increasing his power and in pro- 

 moting his highest interests. In Illinois 

 the local passenger traffic on the railroads 

 is found to vary conspicuously with the 

 difference over large areas in the quality 

 of the soil, though all of the country is 

 well populated. Not only is the number 

 of the passengers in the regions of the best 

 soils several times greater, but the differ- 

 ence in character of the men and women 

 is also evident. The towns in the one case 

 have great business houses, elegant resi- 

 dences, paved streets, electric railroads and 

 lights, fine churches and school-houses, and 

 a progressive, strong, hopeful and happy 

 populace; while in the other these things 

 are noticeably Avanting, except in some 

 measure the numbers of people. These 

 take unconsciously a slower step, require 

 more time in which to transact business 

 and have less relish for physical or mental 

 activity. They are evidently not so well 

 fed and are in consequence really less ca- 

 pable of sustained exertion. Then, too, 

 there is a stimulus in success itself which 

 animates and inspires, while hopefulness is 

 half the battle. Eepeated failure of crops 

 not only discourages the husbandman, but 

 robs the entire commiinity of life and push, 

 and this is as true of mental and moral as 



of physical activities. Soil fertility and 

 man's virility are closely related. There- 

 fore, since certain bacteria have been 

 proved to have direct and very important 

 connection with the former, they have in 

 like measure evident and decided bearing 

 upon the latter. If all flesh is grass, all 

 nutrition as applied to man seems to be 

 ultimately conditioned upon the activity of 

 certain micro-organisms of the soil. 



Man has proved himself to be a mighty 

 master. Formerly the storm-tossed oceans 

 toyed like bubbles with his contrivances and 

 the great billows were barriers to naviga- 

 tion. Now the tempestuous waters are 

 luxuriant pathways of travel, and down in 

 their silent depths they pulsate from shore 

 to shore with vibrant intelligence. Conti- 

 nents are spanned with iron and the mas- 

 sive locomotives thunder over the rivers 

 and plunge under the mountains, defiant 

 of opposition but delicately responsive to 

 human control. How man has swept the 

 forests from the face of the globe, and 

 made at his will the wilderness to blossom 

 as the rose ! The earth, the air, the waters 

 have yielded to him their secrets and the 

 forces thereof have become the obedient 

 servants of his commands. But master as 

 he is, potent as is his sway, he never could 

 have gained a livelihood, nor could he now 

 long maintain existence on the earth, with- 

 out the aid of myriads of invisible, though 

 organized and living, silent though indus- 

 trious and efficient agents of the micro- 

 scopic world. It becomes him, therefore, 

 to seek acquaintance with these beneficent 

 creatures and to find ways and means of 

 favoring their life-giving activities. 



T. J. BuRRILIi. 



UiSrn'ERSITY OF IlLIS"OIS. 



SCIENTIFW BOOKS. 

 The Classification of Flowering Plants. By 

 Alfred Baeton Eendle, M.A., D.Sc, B.L.S., 

 assistant in the department of botany, Brit- 



