425 



snring the leaf I find it to be 50°. Any freely-growing branch would 

 give substantially the same result. I now endeavoured to find whe- 

 ther the curve of the branchlets and the curve of the vein corresponded. 

 The eye at once said they were the same ; but I wished to have cor- 

 rect measurements. This I found to be difficult, inasmuch as the 

 stems are so much larger than the veins, vvhich renders it impossible 

 directly to compare them. Thus it is exceedingly difficult to deter- 

 mine the relative length of the two, so as to take a proportional mea- 

 surement. It occurred to me to try and find the law of the ordinates 

 of the curves, and thus inquire if they corresponded, which I found 

 to be the case, the result showing that the ordinates increased by 

 equal increments in equal spaces, and that the increment is to 

 the absciss. This, then, was the simple law of the curve of the 

 branch. I then proceeded to examine the curve of the vein on the 

 same principle, and found it to obey the* very same law of equal 

 increment in equal spaces. This seemed to me a demonstration of 

 the identity of the curve of branch and leaf 



3. ' On Monstrosities of the Dandelion and common Clover, ob- 

 served near Turin ;' by Charles Murchison, M.D., British Embassy 

 at Turin. In this communication Dr. Murchison noticed the occur- 

 rence of a peculiar state of the common dandelion, in which each of 

 the ligulate florets was supported on an apparent stalk of its own, this 

 stalk being hollow, and probably an elongated, abortive state of the 

 fruit, as indicated by the pappus being at the apex. Some of the hol- 

 low stalks showed a tendency to adhere together. In another mon- 

 strosity of the same plant the flower-stalk divided, immediately within 

 the involucre, into twenty-one tubular pedicels, some of them two 

 inches long, each bearing a small cluster of tubular florets. The 

 inflorescence thus had the appearance of a compound umbel rather 

 than of a capitulum. A general involucre surrounded the pedicels, 

 and a partial involucre existed at the point where the smaller heads 

 of tubular flowers were given off. At the base of the pedicels, within 

 the genei'al involucre, a few sessile, ligulate florets were produced. 

 The monstrosity of the common clover consisted in the conversion of 

 all the parts into green leaves. Each little flower had a tubular calyx, 

 divided into five unequal segments ; and within this were from ten to 

 twenty spathulate, green leaflets, supported on long stalks. The leaf- 

 lets varied in length, from three to six or eight lines. The pistil pro- 

 truded a great way beyond the flower, measuring sometimes an inch 

 in length, and supporting a green leaf, either simple or variously 

 VOL. IV. 3 I 



