186 PHILOSOPHICAL NOTES ON 



it floats, but may have become provided ^Yith other adaptations 

 to enable it to hold its own position in the battle of life, 



I have commenced this discussion by stating that it was 

 suggested that the nodules on the roots of leguminiferag were the 

 result of the action of micro-organisms. It is also stated that 

 when these microbes were prevented from having access to the 

 soil, the nodules ivere not developed. This would appear conclusive, 

 but we have other plants which assimilate nitrogen, without the 

 help of microbes, being traceable, and therefore this function does 

 not appear at present a sine qua non for the absorption of 

 nitrogen. 



There is rather a " rage " just now about microbes, and it 

 seems that nothing can happen without their interference. If the 

 existence and function of this nodule-microbe should become 

 established of course there would be little further to say about it, 

 but one is always reminded that " Listerism " was well established, 

 and eventually became disestablished. 



Under any circumstances, even absurd objections sometimes 

 suggest something of value, and so in spite of the explanation of 

 the nodule by bacteriologists, I leave the foregoing lines as they 

 are, although they may run the risk of being so much waste 

 paper. 



Summary of Chapter. 



After due and unbiassed consideration of the whole question of 

 roots and branches, we seem to arrive at the " moral conviction " 

 that the radicle is only a prolongation or continuation of the 

 plumule stem, with functions suited to a life in the soil, and no 

 essentially different from the stem. We might say that the 

 radicle developes into an underground stem, and the plumule into 

 an above-ground stem. 



We may therefore look upon the finished and highly developed 

 article — the tree, as we see it now on land, as consisting of two 

 main branches, emerging out of the same node. The one growing 

 in the soil and the other growing in the air, the tap-root being 

 the main branch of the one and the stem proper the main branch 

 of the other. 



The air branches are given off regularly, because they have 

 inherited the habit of twisting, in order to expose their leaves as 



