194 HYOSCYAMUS NIGER 



wild or cultivated British biennial plants when about two thirds 

 of the flowers are expanded (B. P.). The dried leaves (Hyos- 

 cyami Folia), collected when about two thirds of the flowers are 

 expanded (I. P.). 1. HYOSCYAMI FOLIA; the leaves: 2. HYOSCYAMI 

 SEMEN; the seed (U. S. P.). 



1. HYOSCYAMI FOLIA. Hyoscyamus Leaves. Henbane Leaves. 

 Collection. The advantage of collecting the leaves of plants after 

 the partial expansion of their flowers has been already noticed 

 under the head of Digitalis purpurea. But the reason why the 

 young branches should be gathered with the leaves, as also 

 directed in the British Pharmacopoeia, has still to be explained. 

 It has been described by one of us in the Pharmaceutical Journal, 

 as follows : Thus after showing the action of the leaves in the 

 formation of the products and secretions of plants, it is stated " that 

 without leaves or other organs of an analogous nature, no growth 

 to any extent can take place, or any secretions be formed" in the 

 plant. Thus the floral leaves and the green parts of the flower 

 have a similar effect to the leaves ; even the young herbaceous 

 parts, from which the leaves and other organs arise, are also 

 directly concerned in the formation of products and secretions. 

 This assimilating power of the young green herbaceous parts is 

 commonly lost sight of, but in reality the structure of these parts 

 is essentially the same as the leaves, except that their tissues are 

 somewhat more compact and differently arranged ; hence, in pro- 

 portion to amount of matter, they do not expose so large a 

 surface to the action of air and light as the leaves, and as the 

 process of assimilation only takes place in the cells immediately 

 below the epidermis, their powers of forming products and secre- 

 tions are somewhat less intense ; but the difference between the 

 parts immediately in contact with the leaves and the leaves them- 

 selves must be very slight. Indeed, it is by no means certain 

 but that the young herbaceous parts frequently contain quite as 

 much, or even more, active secretions than the leaves themselves; 

 thus, if the latter organs be left on the stem till they have passed 

 their active vital condition, the active secretions which they 

 normally contain, will have passed to a great degree into the 



