Earth Builders. 



89 



and thus a great part of the plant food, 

 which plants and animals take from the air, 

 is carried to theocean, necessitating the con- 

 stant and universal activity of life and death 

 to replace it by fresh drafts from the air ; 

 but nature is very economical of her car- 

 bon — animals give it back to the air with 

 every breath, and plants as constantly take 

 it in by their leaves. 



But there is one substance necessary to 

 men and animals, that is the phosphorus 

 which enters into the formation of their 

 bones and brain, which does not exist in 

 the air, nor originally in the rocks. For 

 this necessary substance we are indebted 

 to the fish, which abstracted it from the 

 waters of the ocean, used it to form their 

 own bones, rendered it insoluble in water 

 and left it at the bottom of the ocean, so 

 that, when the continents were upheaved, 

 the ocean mud was full of it ; plants take 

 it from the soil, and men and animals get 

 the necessary supply in their food, and thus 

 it is that man, the highest branch of the 

 tree of life, has inherited the substance of 

 his body, not only from all the past genera- 

 tions of life on earth, but he has also in- 

 herited some of his substance from the 

 fishes which lived and died in the ocean 

 which once flowed over this continent, and 

 from the great creatures which lived on the 

 dry land — the giant saurians of a bygone 

 .age. These giant reptiles, some of them 

 fifty or sixty feet long, which swam in the 

 water, paddled in the mud, and roamed 

 over the dry land, and some of which flew 

 through the air, left us their bones as an 

 inheritance, so that we are their heirs. 



The roots of the tree of life stretch down- 

 ward and backward and derive their sup- 

 port from the earliest creatures that first put 

 on the mystery of life in air and sea, when 

 as yet no part of the earth's crust had 

 raised itself above the ocean's level. 



Every creature that lives is an earth 

 builder ; living it adds daily to the earth's 

 •crust ; dying it builds its body into it. 



Every drop of water in ocean, lake or river 

 is full of living creatures, invisible to the 

 naked eye ; but dying by millions every 

 minute, they fall to the bottom until their 

 remains cover it with a bed of mud of vast 

 thickness. Nothing lives in vain ; crea- 

 tures individually most insignificant, play 

 most important parts as earth builders, and 

 man could no more have existed without 

 the lowly creatures which lived on earth be- 

 fore him, than the topmost branches of a 

 tree could exist if there were no trunk and 

 roots. 



And thus not only in the past, but in this 

 present, the creatures most important to 

 man are the microscopic dwellers in the 

 soil. The farmer ma}^ dress his land with 

 stable manure, but unless these mxinute 

 creatures were present to pass it through 

 their own system, and create a mould of 

 uniform quality, his returns would be but 

 small. 



Some experiments on the value of these 

 minute creatures in converting leaf mould 

 into plant food were recently undertaken 

 by M. Laurent, and published in the Lon- 

 don Lancet, as follows : 



"Seeds of buckwheat were sown in four 

 different kinds of mould. In the first 

 flower-pot natural mould was employed ; in 

 the second the same earth sterilized and 

 then inoculated with bacteria of the soil ; 

 in the third simply sterilized mould ; and 

 in the fourth sterilized mould with the ad- 

 dition of chemical manure. Precautions 

 were taken to prevent contamination of the 

 four receptacles {Journal de Pharniacie et 

 de Chimie, No. 7). The production of 

 wheat in each of the pots respectively was 

 in the proportion of 94, 96, 23, 66. In all 

 the experiments the third series was inferior 

 to the others. The value of microbes in 

 soil rich in organic detritus seems thereby 

 to be proved." 



Who would have supposed that such in- 

 significant creatures could render man such 

 important services ? 



