26 THE AMERICAN BOTANIST 



do under such circumstances, found the world to their liking 

 and continued to live and thrive. 



Germination of Acorns. — It is well known that the 

 seeds of many plants will not grow as soon as ripe, but require 

 a certain period of rest before growth is resumed. In conse- 

 quence of this, it is customary for foresters and nurserymen 

 to stratify the seeds of trees and shrubs in moist sand and 

 bury them in the soil over winter. It now appears, however, 

 that the need of a rest period for some seeds is not as important 

 as has been assumed. A number of specimens are known 

 whose seeds under proper conditions will grow as soon as 

 ripe, and in the case of the tomato, seeds taken from green 

 fruits have been known to 1 sprout. Beans will often sprout 

 in the pod if the late summer happens to 1 be moist. Probably 

 the most celebrated instance of seeds sprouting while yet 

 attached to the plant is afforded by the mangrove (Rhico- 

 phora mangle) in which the seeds develop into young plants 

 of considerable size before separating from the parent plant. 

 This phenomenon has been found, though in a lesser degree, 

 in some of our oaks. In the red oak it is found that the 

 young plant after filling the seed, continues to develop while 

 still attached to the tree. Dr. John H. Harshberger has in- 

 vestigated other oaks and finds that the acorns of the white 

 and black jack oaks will grow as soon as ripe if the shells 

 are not allowed to become dry. That the seeds of the white 

 and red oaks will grow the same season they are produced 

 has long been known. Under favorable conditions one is 

 likely to find, late in fall, that the acorns have already pushed 

 down good-sized roots though no sign of a shoot will be 

 visible until spring. 



