132 NATURAL HISTORY OF PLANTS. 



liberian tissue forming long continuous tubes, anastomosing more or 

 less frequently, according to the species — very rarely in Papaver 

 xomniferu))). 1 In the calyx and fruit they form, on the contrary, a 

 very intricate network. In the root of Argemone we see the rows 

 of laticiferous cells which are destined to be transformed into anas- 

 tomosing tubes. This condition, rows of cells forming a network 

 with other rows, is permanent in Sanguinaria Canadensis, where we 

 also find isolated latex cells, and in the petals continuous tubes. The 

 laticiferous cells of Chelidonium vary in form, according to the part 

 they occupy. In the cortical parenchyma and medullary rays they 

 are short. In the liber they are elongated like the fibres thereof. 

 In Bocconia (Maclei/a) cordata their distribution is nearly the same. 2 

 The reservoirs of latex found in the liber appear to be true liber fibres, 

 and differ in no respect from the rest of them when the contained 

 latex has disappeared with age ; this occurs gradually, from below 

 upwards. 3 In Glaucium the latex is in isolated cells which in the 

 stem are early emptied. 4 Some rows of cells with yellow latex are 

 found in the outermost layers of the root. In the various plants of this 

 order the reservoirs of latex communicate either with one another 

 by perforations or special canals, 5 or with the various lymphatic 

 vessels ; and even in Jrgemone, Trecul has seen the formation of latex 

 in situ in the cavity of certain vessels, and stopping up their channels. 6 



The plants of this order owe their most marked qualities to the 

 presence of these juices; 7 where the latex is abundantwe find poisonous, 

 narcotic, acrid, irritant, or evacuant properties usually very marked. 

 The Poppies are essentially opium plants, and this terrible poison or 

 heroic remedy, is an integral part of the latex, or rather is only the 

 thickened latex, deprived b} r desiccation of the greater part of its water. 

 This juice is found in most parts of the plant, fruit, calyx, leaves, 



1 Far more frequently in tbe Red Poppy. meet, often touch by their summits, and then 



a There are cells with yellow orange or red blend by the absorption of their walls at the 



latex, "scattered through the bark and me- point of contact. 



dullary rays, and between the vessels of the 6 At first these form yellow protuberances on 



wood." the inner wall of the vessel, limited by a very 



3 At a certain age it is confined to the peri- delicate membrane, which then meet in the centre 

 carp. of the channel, and sometimes fuse. 



4 Only a little brown granular matter is left 7 DC, Ess. sur les Propr., 107. — GtUB., 

 in the cells round their walls. Drog. Simpl., ed. 6, iii. 695. — A. Rich., EUm., 



5 In Argemone bays form in the neighbouring ed. 4, ii. 407. — Endl., Enchirid., 444. — Lindl., 

 sides of two parallel vessels, and advancing to Veg. Kingd., 431 j Fl. Sort., 15. — Pebeiba, 



