534 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



LIFE A DIEEOTOE OF FOEGE IN THE DEVELOPMENT 

 AND EVOLUTION OF PLANTS. 



By Eev. Professor G. Henslow, M.A., V.M.H. 



[Bead October 25, 1910.] ' |' 



Tt was customary formerly to describe life as a " Vital Force," but 1 

 the inadequacy of the expression has been recognized and the term 

 abandoned. It was, I believe, Mr. James Groll who first drew atten- \ 

 tion to the question forming the title of his pamphlet, "What 

 Determines Molecular Motion? The Fundamental Problem of 

 Nature.""^ The fact is that the world is only composed of various '\ 

 kinds of matter — made of the eighty or so elements, every one of which 

 is of itself lifeless and inert — and force, and no force can direct itself 

 or purposely bring about molecular motion or any other movements of 

 matter. 



Force in action requires something to direct it. Thus a stone 

 falls perpendicularly to the ground under the direction of gravity. 

 Elements combine to make compounds under the direction of what is 

 called chemical affinity ; but no one knows why it is so, or the source 

 of this directivity. 



One thing is observable, and that is, in the inorganic world such 

 directions are constant and always the same. The molecules of a 

 crystal are so placed as always to make the same angles, whether 

 to-day or millions of years ago. Gravity has never altered. But 

 when we come to living beings it is very different, as I propose show- 

 ing ; but whence came the first living being ? 



One of the simplest forms of living plants may be seen in the | 

 zoospores, or propagative bodies of some green sea-weed, as the j 

 common Ulva, or laver. They consist of living protoplasm without any 

 cell- wall encasing and protecting it. After they settle down, cell- 

 walls of cellulose are secreted by the protoplasm. Such, then, may ' 

 be regarded as probably being something like the first living plant on 

 the earth. But how did life arise? f 



This question demands a previous one. How was protoplasm 

 formed? Most substances are compounds with comparatively few 

 parts or atoms of each element; thus water is H2O, sugar GiaHgoO^i; 

 but the approximate analysis of albumen, which is akin to protoplasm, 

 is GgoHioQNjg02o, protoplasm requiring sulphur and, in its all-impor- 

 tant nucleus, phosphorus. Whence came these elements together; 

 and why did they unite in the proper proportions to make protoplasm? 



* Philosophical Magazine, July, 1872. 



t For further considerations about this, the reader is referred to my 

 Present-day Bationalism Critically Examined, chaps, iv., v., pp. 28 ff. 



