POISONOUS PLANTS 215 



in the distillate. In the absence of definite chemical tests 

 the effect on a mouse or frog should be observed. 



EEPBEENCES TO HEMLOCK. 



1 C. Aggio, Vet. Jl., 1907, p. 599. 



2 "W. Graham Gillam, Vet. Becord, 1906, p. 88. 



3 W, Graham Gillam, Vet. Becord, 1897, p. 703. 

 * B. Freer, Vet. Becord, 1893, p. 3. 



^ L. T. Barker, Veierma/rian, 1873, p. 601. 

 ^ J. Gerrard, Vetervna/riam, 1873, p. 107. 

 ^ Holford, Veterina/riom, 1841, p. 600. 



Cicuta. 



Botanical Characters. — Cicuta virosa (Fig. 29), cow- 

 bane or water hemlock. Stem hollow, spmewhat branched, 

 attaining 3 or 4 feet. Leaves twice or thrice pinnate or 

 ternate, with narrow lanceolate acute segments, 1 to 

 li inches long, bordered with a few unequal acute teeth. 

 General umbels of from ten to fifteen or' even more rays. 

 Bracts of the partial involucres subulate, not quite so long 

 as the pedicels. The habitat is in wet ditches and on the 

 edges of lakes, and it is very local in England, Ireland, and 

 southern Scotland. 



The roots are hollow and septate in structure, from 2 to 

 4 inches long, and about 1 J inches in diameter, and marked 

 by transverse scars of leaf bases. 



The Cicuta species are confined to the Northern Hemi- 

 sphere. In America, C. maculata, water hemlock or beaver 

 poison, is abundant in the United States. C. vagans has 

 killed cattle in Oregon and Washington, and C. bolanderi in 

 marshy land in California has also been reported. 



Toxic Principle. — The poisonous principle is not known 

 with certainty ; the roots contain a yellowish acrid juice of 

 peculiar smell, and a small quantity of a terpene, but no 

 volatile alkaloid. According to Dragendorff there is an 

 active principle, which has been called cicutoxin, classed by 

 Cushny in the picrotoxin group. E. M. Holmes, F.L.S., 



