146 



THE AMERICAN BOTANIST 



the protection of these scales a new set of embryo leaves de- 

 velop and soon a new bud is ready to endure the winter and 

 continue the stem another year. While this new bud is form- 

 ing, other new buds appear in the axils of the old leaves and 

 the following year produce side shoots or twigs with their ac- 

 companying leaves. As is well known, when one set of leaves 

 fall another set is never produced in their places. A twig has 

 leaves upon it only during the season in which it is formed. 

 According to Apgar's "Ornamental Shrubs of the United 

 States," however, a Japanese tree, CcrcidofhyUnin Japonicuin ^ 

 produces new^ leaves annually in place of the old leaves until the 

 twigs have reached a diameter of an inch or more. There seems 

 to be some mistake, here, however. Leaves always arise from 

 buds and we query whether it is not possible that the appear- 

 ance of a single leaf may be explained as arising from an 

 auxiliary bud and thus only apparently arising from the old 

 leaf scar. 



Distribution of Cacti. — It is the general impression 

 that all members of the cactus family are natives of America, 

 but C. K. Dodge, of Port Huron, Michigan, questions this 

 opinion. The eleventh edition of the ''Encyclopedia Britan- 

 nica" intimates that there are some species in tropical Mada- 

 gascar and the "Encyclopedia Americana" says that there is 

 one species in Ceylon which was known to the ancient Greeks 

 and Romans. The word cactus is found in the languag'e of 

 both these peoples. Other cyclopedias mention cacti as natives 

 of the Old World and the "Illustrated Flora" of Britton and 

 Brown speaks of the group as nearly all native of America. On 

 the other hand Wood's "Class Book of Botany" says all the 

 species are American and so does Kerner and Oliver's ''Natural 

 History of Plants."' Ellsworth Huntington, who has for some 

 time been making a study of desert conditions in both Hemis- 

 pheres, says that there are no cacti in the Old World. The 



