59 



minute shoot, is the plumule. The radicle of the embryo 

 always points towards the micropyle. The position of the 

 embryo in the albumen is often characteristic ; it may be 

 straight or curved, it may be in the centre of the albumen 

 (axial), eccentric, or external to it as in Grasses. The cotyledons 

 may be placed straight in the seed or variously folded. The 

 cotyledons are : 



incumbent, when the radicle is laid along the back of 



one cotyledon ; 



accumbent, when the radicle is laid along the edge of 

 the cotyledons. 



In exalbuminous seeds all the food material is stored in 

 the tissue of the embryo itself, and usually in the cotyledons, 

 which are then thick and fleshy. In other cases the cotyledons 

 are thin and more or less foliaceous. On germination taking 

 place the cotyledons may remain below the ground, as in the 

 Oak, see Figs. 1 and 2, Plate I, or be raised up on the growing 

 stem into the light and air, when they usually become green 

 and more or less like ordinary leaves, as in Oroxylum indicum, 

 see Plate XII. The portion of the stem of a seedling situated 

 below the insertion of the cotyledons is called the hypocotyl Hypocotyi. 

 while that part of the stem lying between the insertion of the E P lcot yi- 

 cotyledons and that of the first foliage leaf or leaves is the 

 epicotyl. 



The plants termed Angiosperms, which have been men- Monocotyie- 

 tioned above, are sub-divided into two great groups known 

 as the Dicotyledons and Monocotyledons respectively. In the dons, 

 former, which includes most of our important forest species 

 the embryo has typically two opposite cotyledons'; in th3 

 latter, which includes such plants as the Grasses, Bamboos 

 and Palms, the embryo has typically only one cotyledon. 



55. The mature gyncecium of a Fruit. 



flower containing the seeds, with everything which may be 

 joined to it, constitutes the fruit. The fruit may consist 

 of a single ripe pistil, in which case it is a simple fruit, 

 or of the collection of separate pistils belonging to one 

 flower when it is an aggregate fruit, or of the pistils belonging 

 to several flowers united together, when it is a multiple fruit, 

 or infructescence. If it is provided with a stalk the fruit is 

 said to be stipitate, if not, it is sessile. 



The ovary wall becomes the wall of the fruit which is" 

 called the pericarp and this immediately surrounds the seeds. 

 The position occupied by the embryo with reference to the 

 rest of the fruit is important, and the radicle is said to be 



