THE AMERICAN BOTANIST 31 



North-eastern States, for example, the magnolia, catalpa, paw- 

 paw, sour gum, red-bud, and others with this type of leaf, have 

 pushed in from the South. The cause of entire leaf-margins 

 seems to be found in temperature and moisture; regions that 

 are either physically or physiologically dry and those in which 

 great transpiration must occur produce the greater number of 

 such forms. 



Alkaloids of Belladonna. — The belladonna plant 

 (Atropa belladonna) though very poisonous is highly re- 

 garded as a drug plant, being almost indispensable in dilating 

 the pupil of the eye when an examination of that organ is nec- 

 essary, and equally useful in other ways. The supply of bella- 

 donna, like that of most of our drug plants, has hitherto been 

 derived from wild specimens, but an investigation of such ma- 

 terial has shown that the alkaloid, the part effective as a drug, 

 varies greatly in different plants. The, question then arises, 

 can the plants be bred up to produce not only a more uniform 

 alakloid content, but a higher percent of this substance as well. 

 This question the investigators in the national government 

 service have answered in the affirmative. Analysis of wild 

 plants showed a difference in alkaloid content of nearly 300 

 percent, and by breeding from the plants with the highest per- 

 centage of alkaloid, this amount was still further increased. 

 Subsequent cultivation has shown that plants with a high alka- 

 loid content have no tendency to deteriorate in this respect. 

 Since the physician must depend upon the pharmacist for the 

 drugs he administers it is highly desirable that a given dose 

 shall contain the full amount of the principle involved. The 

 production of drugs of known strength, therefore, must be a 

 long step in advance of present methods. 



Iris Bracteata. — The British Botanical Magazine for 

 December, last, figures in color an interesting iris that does 

 not seem to have come into cultivation on this side of the 

 world, though it is an American plant. The plant is Iris brae- 



