Ansfewandte Botanik. 95 



*t3 



tioned the occurrence of both resin-cells and mucilage-cells, of which 

 the former generally contain some drops of ycllowish oil besides 

 the solid resin. In the mucilage-cells the cell-membrane usually 

 exhibits a more or less distinct layering, and the lumen may be 

 almost obsolete. In regard to the distribution of these cells, the 

 mucilage-cells abound in the palisade tissue of the leaves, but are 

 scarce in the pneumatic tissue; they are, moreover, very frequent 

 in the stein, in the bark and pith for instance; in the root they 

 occur in the primary, and secondar}^ cortex. The oil cells are distri- 

 buted in the chlorenchyma of the leaf, especially the pneumatic 

 tissue, also in the collenchyma, which accompanies the larger veins. 

 They are, moreover, to be observed in the stem, in the cortex, and 

 in the parenchj^-ma of the hadrome; in the root they are quite fre- 

 quent in the primar^^ and secondarj^ cortex, besides in the hadrome. 

 Characteristic of the root-structure is the presence of numerous, 

 isolated fibres of true stereome in the leptome. The stem possesses 

 hypodermal strata of collenchyma, and scattered groups of sclerotic- 

 cells occur in the cortex proper. No endodermis in developed, and 

 the pericycle of the young shoot represents merely isolated arches 

 of thickwalled stereome on the leptome-side of the mestome-strands. 

 The pith consists of a peripheral, active, and starch-bearing portion, 

 and an inner, inactive. When held toward the light the leaf shows 

 a number of translucent spots, due to the abundance of mucilage- 

 cells. Unicellular, pointed, long, and thickwalled hairs abound on 

 the dorsal face of the blade, parth^ covering the stomata, which 

 have one pair of subsidiary cells parallel with the Stoma; the pali- 

 sades are high, and very compact, covering a more open pneumatic 

 tissue. H^'podermal layers of collenchyma, and a stereomatic peri- 

 c^'^cle accompany the veins. Theo Holm. 



Holm, T., Medicinal plants of North America. 24. Cicuta ma- 

 culata L. (Merck's Report. XVIII. p. 35—38. f. 1 — 12. Febr. 1909.) 



This extremeU^ poisonous plant was formerly considered as a 

 medicinal plant of great importance, but is now rarely, if ever, used. 

 The whole plant, especially the roots, is poisonous, and in its 

 effect closely analogous to C. virosa of Europa. A resinous substane, 

 cicutoxin, has been found in the vegetative organs, while a volatile 

 alkaloid, cicutine, has been extracted from the fruits. In cases of 

 poisoning the plant operates on man as an acrid narcotic, producing 

 vertigo, intoxication , and convulsions, followed by general paralysis 

 and death. The internal structure is described, and illustra.ted. When 

 fully mature the secondary roots are tuberous, oblong, and termi- 

 nated by a long, filiform apex, the lateral branches of the roots 

 are slender and remain so. The thick, tuberous portion contains a 

 broad, secondary cortex with several Strands of secondary leptome, 

 oil-ducts, and large deposits of starch. Cork and a few strata of 

 collenchyma are developed from the pericambium, replacing the 

 peripheral tissues from epidermis to endodermis incl. , which soon 

 are thrown off. The central part of the root contains no pith, but 

 only the primary vessels, and a little conjunctive tissue. In the stem 

 there are Strands of hypodermal colenchyma corresponding with 

 the mestome-strands, w^hich constitute a circular band with a con- 

 tinuous sheath of thickwalled libriform; this sheath is said to lack 

 in C. virosa, in accordance with Noenen. No endodermis, and no 

 pericycle was observed in any parts of the stem. 



