14 THE OAK 



the egg-shaped body consists chiefly of two longitudinal 

 halves, separated by a median plane which runs through 

 the acorn from top to bottom. These two halves, lying 

 face to face so closely that it requires the above manipu- 

 lation to enable us to detect the plane of separation 

 (fig. 2, Z), are not completely independent, however ; at a 

 point near the narrower end each of them is attached 

 to the side of a small peg-shaped body, with a conical 

 pointed end turned towards the narrow end of the acorn. 

 This tiny peg-shaped structure is so small that it may 

 be overlooked unless some little care is exercised, but if 

 the hard masses are completely torn apart it will be 

 carried away with one of them. 



The two large plano-convex structures are called the 

 cotyledons ', or seed-leaves (fig. 2, c) and they, together 

 with the small peg-shaped body, constitute the embryo of 

 the oak. The peg-shaped body presents two ends which 

 project slightly between the two cotyledons beyond the 

 points of attachment to them ; the larger of these ends 

 has the shape of a conical bullet, and is directed so that 

 its tip lies in the point of the narrower part of the acorn, 

 the other, and much smaller end, is turned towards the 

 broader extremity of the acorn. The larger, bullet-shaped 

 portion is termed the radicle (fig. 2, r), and will become 

 the primary root of the oak-plant ; the smaller, opposite 

 end is the embryo bud, and is termed the plumule (fig. 2, 

 pZ), and it is destined to develop into the stem and leaves 

 of the oak. If the observer takes the trouble to carefully 

 separate the two large cotyledons, without tearing thi'iii 



