5 



HOW PLANTS GROW. 



Without entering into any elaborate explanation of the varied phenomena 

 of plant growth, a simple and easy performed experiment will furnish an 

 interesting illustration which will convey a very tangible idea of the elemen- 

 tary processes of plant nutrition and growth. Procure a penny worth of 

 mustard and cress seeds from a seedsman, then soak a piece a flannel in 

 water and scatter a few seeds on its surface. Keep the flannel moist, a good 

 way being to put it in a small common flower pot, and set it in a saucer 

 containing a little water, when the moisture will rise up through the flannel 

 and keep the surface damp. Place the pot in a moderate and equable 

 temperature, an ordinary sitting room will answer quite well, and in twenty- 

 four hours it will be observed that the seeds have swollen to twice their 

 original size. This is caused by the water which they have imbibed, it will 

 also be noted that the outer skin of the seed has burst, and a small worm- 

 like body is being protruded. These are the young roots, and by the second 

 day they will be seen to have increased considerably in length, and in what- 

 ever position the seeds have fallen the young roots will have all turned 

 downwards, arid the extremities are seen endeavouring to burrow into the 

 substance of the flannel, seeking towards darkness and moisture. By the 

 third day they have become greatly elongated so as to raise the whole seed 

 upwards, and they have also developed numerous small white hairs, which 

 also closely adhere to the surface of the flannel. These act the part of mouths 

 or suckers and greedily drink up the water which is employed in this 

 transmutation of substance. By this time the roots having secured an 

 anchorage by these holdfasts, the infant stem is seen struggling to free itself 

 from the swaddling clothes of the seed covering, and to emerge upwards into 

 the air and light. By and bye it shakes off the brown ruptured seed coat 

 and displays two flat, roundish, smooth green leaves in the case of the 

 mustard and two cleft or fingered ones in the cress. In the course of a few 

 days the stem has grown considerably and elevated the seed leaves an inch or 

 two above the surface, whilst the roots have penetrated some distance into 

 the flannel. In about a week's time they will have attained their full 

 growth, when they will remain stationary for another week and then gradually 

 wither away. This is the process known as germination for which three 

 things are absolutely necessary, viz. — air, warmth, and moisture and by the 

 aid of these, the vital forces stored up in the seed are able by nature's 

 wonderful alchemy to transform the apparently dead inert substance of the seed 

 into the living growing plant. An exactly similar process is seen in the 

 manufacture of malt, where the barley is allowed to sprout to a certain extent 



