36 Journal of the Mitchell Society '[May 



I forget how far I entered into this matter in my last, of Feb. 

 21st, but if I should repeat myself here you will forgive me. 



You know how a bean and a pea germinate : both with thick 

 fleshy cotyledons which do not expand into leaves, as many 

 plants do. The diiference between them is that the cotyledons 

 of the pea remain under ground, while the bean's are elevated 

 on the stem above it. 



Well, the acorns behave like the pea, but the cotyledons re- 

 main enclosed in the shell while their stems or stalks, or peti- 

 oles come out and enclose between them the stem which grows 

 up. If you pick up any seedling oak, you will find it so, and 

 removing the shell, you can separate the cotyledons from one an- 

 other and examine the whole arrangement. 



In most white-oaks the stems are longer, in the black-oaks 

 shorter, and that is already seen in the acorn itself. In the 

 live-oak it is longest already within the acorn, and in all of them 

 it lengthens in germination more or less. 



The question with me now is, how soon does the tuber in the 

 live-oak swell and how long does it last. 



I suppose that it begins to swell immediately when formed, 

 attaining its full size, perhaps, in the fall, or it may grow for 

 several years. I have a young live-oak, apparently three years 

 old, with the biggest tuber I have ever seen. 



And I suspect that the tuber is hardly absorbed but gradually 

 merged into the root " 



On April 7th, 1880, he writes again: 



"Wm. St. J. Mazyck, Esq., 



Dear Sir: — Enclosed please find the results of my studying 

 of the germination of acorns and of their structure. 



In regard to the germinating Q. virens we ought to know yet: 



1st. How soon the tuber forms : from your many accounts I 

 judge that it forms before any leaves are developed. 



2nd. When the cotyledons are exhausted and what relation 

 their increase bears to the increase of the tuber. 



How long the tuber continues to grow larger, and at what age 

 of the plant it becomes merged in the root or base of the trunk. 



I have a specimen about four or five years old, in which the 

 tuber is the largest of any I have ever seen, but, of course, hard 

 and ligneous. 



