and Coagulation of Fibrin without Evolution of Ammonia. 209 
are larger and more distinct still; and of intermediate size in 
some species of Carduus. 
Again, in other plants the molecular base may be present in 
the latex, and the fibrin quite absent, while another matter 
appears. This may be well observed in some Euphorbiacez. 
Thus in Euphorbia Lathyris and E. Peplus the latex will often 
not, and perhaps never will, coagulate spontaneously, and is 
httle affected by the addition of water, while the latex of E. exi- 
gua is quickly coagulated by water. The liquor laticis and the 
molecular base giving opacity to the latex certainly exist to- 
gether in Euphorbiacee. But the most remarkable objects in 
this juice are staff-like bodies, about ;4, inch long and 5755 
thick. These measurements were obtained in EF. Lathyris; 
but they differ considerably in different species, and the ob- 
jects are either swollen in the centre, like a rolling-pin, or with- 
out any such swelling, like a rod. I have examined most of the 
British species of this genus, and never found these staff-like 
bodies absent. By iodine they are instantly made much 
more distinct, and of a very dark-blue colour, while the mole- 
cular base and its fluid are only tinged yellow. Hence they 
would appear to be a form of starch, and might be called starch- 
sticks ; and by them alone the latex of Euphorbiacee is very 
easily and certainly distinguishable from that of other orders of 
plants *. 
The precise use of the vegetable latex is mere matter of con- 
jecture. If, as Dr. Lindley reports (‘ Elements of Botany, Struc- 
tural, Physiological, and Medical,’ p.9), it be conveyed to the 
newly formed organs, we may well suppose it, like the chyle of 
the highest animals, to be a provision for growth and nutrition, 
especially now it is shown how commonly the latex is composed 
of the molecular base and of either fibrin or starch, independently 
of whatever albumen may coexist with these. 
Two hypotheses as to the origin of fibrin have been current 
in our day :—the first, entertained more than a century since by 
Sydenham, Quesnay, and Bordenave (Introduction, pp. xxvii.— 
xxvill., to the Sydenham Soc. edition of Hewson’s Works), and 
revived subsequently, that the fibrin is formed at the expense of 
the red corpuscles of the blood; the other, very recently popular, 
that the fibrin is produced by the agency of the pale globules. 
But now we find this vegetable fibrin certainly without any free 
or floating cells at all. 
There are two other points of view in which the characters 
* Since the above was printed, I find that these bodies have been well 
described in Euphorbiacez by Schultz and others. The late Mr. Quekett 
figured them, like two-headed clubs, in E, splendens, 
