40 AGRICULTURAL RESEARCH AND THE FARMER 



CHAPTER III. 



PLANT PHYSIOLOGY. 



Plant Physiology may be defined as the study of the life 

 processes of plants, and how they are affected by the conditions 

 under which the plants live. The question is one of fundamental 

 importance. It is hardly too much to say that our lack of 

 knowledge in this matter is the most serious limiting factor in 

 the efforts now being made in other departments of science to 

 devise methods of improving the health and yield of crops, 

 and of treating the diseases to which they are subject. Perhaps 

 a simple illustration, drawn from commercial life, will help to 

 make this clear. We may conceive of a traveller from a foreign 

 country landing at the port of London. He wishes to go to 

 Newcastle, but he does not know where Newcastle is, he 

 only knows that there are important shipbuilding works some- 

 where on the East Coast which he must visit for the purposes 

 of his business. He could charter a ship and travel slowly 

 up the East Coast, putting in at various ports on the way, 

 until he came to the city he wishes to visit. But this would 

 be a long task, and he happens to know that there are 

 railwaj^ lines in the country diverging from London, and 

 that one of them would probably lead to Newcastle. He does 

 not know, however, which station to go to, so he might have 

 to take a motor car and travel round from one station to another 

 until he comes to the right one, and then he must find out what 

 trains are running and when. This is the empirical method 

 of finding the best way of getting to Newcastle, and with patience 

 and perseverance the traveller would doubtless be successful in 

 reaching the city in course of time. But if he wanted afterwards 

 to go on from Newcastle to Manchester, or if, on returning to 

 London, he wished to go to Birmingham, he must go through 

 the same process of trial and error again, and in the long run 

 the time wasted in this way would be very considerable. For- 

 tunately for the traveller, however, there is such a thing as a 

 Bradshaw's Railway Guide, which may be compared to the 

 product of fundamental research, for it contains the results of 

 a detailed investigation of the railway system of the United 

 Kingdom. The traveller has only to consult this reference book, 

 and he can readily see how to get from London to Liverpool, 

 or from Devizes to Darlington, or from Cork to Killarney. 

 Originally the book must have taken an enormous amount of 



