EEASONS WHY ORGANS MAT GROW WITHOUT LEAVES. 17 



which. I have never suffered, even in the driest season. Now for the 

 conflrmation of your statement, that plants will increase in bulk in the 

 absence of leaves. Early in September, when the roots had reached 

 their state of complete organization, when the tops had grown from 

 two and a half to three feet in height, the lower leaves generally 

 extending five feet wide, I began to out the tops as they were wanted 

 about half an inch from the crown; and from that time to this the 

 bulbs have been proved by actual measurement to continue to grow, 

 and are throwing out, aU round the crown, a fresh supply of luxuriant 

 leaves for another feed. From this source the bulk of keep for my 

 cattle has been enormous; and the importance of such a supply 

 at a time when, in conrmon seasons, the Grass begins to fail, is 

 beyond a doubt, especially for growing stock, since it has been proved 

 that the leaves of the Turnip contain more of the bone-making 

 material than even the bulb itself. I claim no merit for this experiment 

 as a novelty, for there is a report of a somewhat similar process in the 

 Prize Essays of the Highland Agricultural Society, vol. iii. ; the only 

 difference being that in that instance the Swedes had been transplanted. 

 I would add, that it is there shown, besides, that, on analysis, as com- 

 pared with Swedes treated in the common way, the root only suffered in 

 value to the extent of containing a small per centage more of water, the 

 quantity of solid matter being displaced in the same proportion, while 

 the quality of the food remained uninjured." The practice of cutting 

 off the Potato haulm in order to arrest the Potato disease, one of the 

 best remedies for the evil yet known, points to the same general fact. 



It must, however, be borne in mind, tbat we have no warrant 

 for supposing that roots can grow in the absence of branches 

 and leaves, until roots have arrived at a state of complete 

 organization. If a plant producing tubers loses its top when 

 the tubers are young, the latter perish or cease growing ; but if 

 the tubers are considerably advaiiced in formation, then they 

 will continue to grow, notwithstanding the loss of the leaves. 

 It would seem from this undoubted fact that a considerable 

 amount of vital force is required in order to render a plant 

 independent of its green organs ; but that it becomes indepen- 

 dent as soon as that amount, whatever it may be, has been 

 acquired. In the beginning the green organs, exposed to light, 

 appear to possess exclusively the property of elaborating the 

 aqueous and gaseous matters which they absorb, and of so 

 forming the material out of which growth or increase of size 

 elsewhere is provided for. This operation takes place at that 



