284 Experiments on the Growth of Bulbiferous Plants. 



former. The portion of the leaf beneath the last thread and 

 the bulb was two inches. The growth of the plant produced 

 the following changes in the length of each of the above- 



mentioned divisions. 



Dimensions of the 

 entire leaf. 



Dimensions between the Threads. 



From the Apex 

 to the First. 



From the First 

 to the Second. 



From the Second 

 to the Bulb. 



Feb. 14. 7 inches. 



15. 7f inches. 



16. Scinches. 



18. 8^- inches. 



■ 20. 9£ inches. 



23. lOf inches. 



One inch. 

 No change. 

 No change. 

 No change. 

 No change. 

 No change. 



4 inches. 

 No change. 

 4-J- inches. 

 4£ inches. 

 4-^ inches. 

 4i inches. 



2 inches. 

 2|. inches. 



3 inches. 

 3§ inches. 

 4i inches. 

 5i inches. 



From this experiment it appears that, in eight days, the 

 leaf had increased nothing within an inch of the point ; that 

 it had increased one third of an inch only within six inches 

 of the point; and that, between this point and the bulb, the 

 increase was three inches and half an inch ; demonstrating 

 that the whole of the increments of growth had been deposited 

 at the base of the leaf, whilst the apex remained unchanged 

 and was carried upwards. It was still, however, necessary to 

 ascertain, whether the apex of the leaf possessed any influence 

 in affecting the growth of the base? and whether the sap, 

 which produced the increase, was first raised to the point of 

 the leaf? To answer these queries, I. made the following 

 experiment. 



I took a Jonquil which, on the 20th of March, had four 

 leaves, each eight inches long. I cut off one leaf, a, at the 

 height of two inches from its base ; another, b, at four inches 

 from its base; a third, c, at six inches from its base ; and left 

 the fourth entire. Through the middle of the remaining 

 portion of b, that is, two inches above its base, I passed a 

 silk thread ; through c I passed, also, two silk threads, one 

 at two inches from its base, and the other two inches above 

 the former, so as to divide the portion of the leaf into three 

 equal divisions ; and in the same manner divided d, the entire 

 leaf, into four equal divisions, one of which necessarily con- 

 stituted two inches of apex. The result of the growth of 

 the leaves, at the end of three weeks, was the following : — 



a had elongated half an inch only, and had become greener 

 at the base. 



b had elongated three-fourths of an inch, and was, also, 

 greener at the base. 



