142 LETTER X. 



are the cotyledons; the little conical part at one end 

 (e.) is the radicle, and the small scale-like body which 

 lies between them in the inside {d.) is the plumule, 

 or vouno- stem. 



Still more curious than those of the Hazel are the 

 changes that occur during the growth of the fruit of 

 other genera of the Oak tribe. In the Oak itself the 

 involucre is formed of a great many rows of scales, 

 which gradually grow larger and harder, and more 

 numerous, and at last become what you call the cup 

 of the acorn ; a part you would never have guessed 

 could have been made out of a number of little leaves, 

 if you had not watched their successive changes. 

 The ovary at first contains three cells, and each cell 

 two young seeds ; but in obedience to the constant 

 command of nature, one of the seeds grows faster 

 than the rest, presses upon the other cells and seeds, 

 gradually crushes them, till at last, when the acorn 

 is ripe, all trace of them has disappeared. 



In the JBeech, the involucre originally consists of a 

 vast quantity of little thread-like leaves, which en- 

 close a couple of pistils. These leaves gradually grow 

 together, and over the pistils, so as to form a prickly 

 hollow case, which completely encloses the nuts ; at 

 last, the case rends open spontaneously into three or 

 four woody pieces, and makes room for the nuts, or 

 mast, to fall out. As in the Oak, one of the ovules 

 destroys all the others, so that out of six young 

 seeds, but one is found in the ripe nut ; here, how- 

 ever, you may generally find the five that have 



