SUMMER MEETING AT BROOKFIELD. 97 



while those who know nothing but isolated facts soon get into the same 

 fix as the boarding-school girl who has studied everything from ABC 

 to astronomy : they know too much to know anything. Agricultural 

 papers should also publish a progressive course in botany, prepared by 

 a practical botanist who understands the needs of those who read such 

 papers. This, of course, could not take the place of the special topics 

 discussed in such papers, but a course of fifty-two short lessons on 

 practical botany, so arranged that a person of ordinary understanding 

 could begin at the first and master one every week, would greatly 

 increase the value of the paper to most readers. 



I can attempt nothing like a progressive course in the short time I 

 have this evening, but I will endeavor to give you a few points relating 

 to plant life that may be of use as well as interest to most of you. We 

 will first consider 



PLANT LIFE AND GROWTH. 



All plants are made up of small bodies called cells. Some of the 

 lower forms of plants consist of only one or a few cells, but most plants 

 have millions of them. If we cut a thin section of any part of a plant 

 and examine it with a good compound microscope, we will find that the 

 section consists of cells arranged side by side and one over the other 

 in a definite order. The cells may be either alive or dead in a living- 

 plant. Most of the cells of large plants are dead, even when the plant 

 as a whole has vigorous life. It is very important to understand the 

 nature of these cells; for without this knowledge, no one can form any 

 correct notion as to the manner in which plants grow. A cell in its 

 simplest form is a globular body that has a somewhat tough outside 

 wall and a fluid interior. The fluid inside is called bioplasm, and has 

 the power to draw more fluid to itself through the wall that encloses 

 it, and thus increase the size of the cell. This growth of the cell goes 

 on for some time, but soon the cell reaches its normal size, and can 

 grow no longer as a single cell. It then divides itself into two or more 

 cells by the constriction of the cell-wall, just as a butcher divides his 

 sausages into rings by tying strings around them. Each of the parts into 

 which the cell has been divided then grows to the size of the original 

 cell, when division goes on as before. After a certain time, the cell 

 loses the power to thus divide itself, on account of the gradual thicken- 

 ing of the cell-wall, and the iuterior becomes filled with hard material. 

 But before this happens, most cells are squeezed into various shapes, 

 differing more or less from the original spherical shape. When a cell 

 has lost its bioplasm (and with it the power of self-division), it is said 



h r— 7 



