CHAP. V. FUNCTION OF REPRODUCTION. 27 1 



cha^ze is removed from the hilum, so that the whole 

 nucleus is inclined upon the axis, as described in art. 

 266'. the ovule is termed " Anatropous" (A). It 

 more frequently happens that the chalaze is immedi- 

 ately opposite to the hilum, and the foramen near it 

 (as at A) ; but sometimes the former is placed on one 

 side, at about a quarter of the circumference of the 

 ovule. 



(268.) Formation of the Embryo. Such is the 

 state of the ovules previous to the action of the pollen 

 upon the stigma. Sooner or later after that action, the 

 embryo makes its appearance under the form of a 

 minute vesicle, attached to the summit of the inner- 

 most or embryonic sack, with the radicle directed 

 towards the foramen, and the cotyledons towards the 

 chalaze. It gradually enlarges, and the whole ovule 

 also continues to increase. 



(269.) Formation of Albumen. Whilst the ovule 

 is increasing, the testa and tegmen gradually part with 

 their juices, for the support and increase as it should 

 seem of the nucleus; and these two integuments are 

 ultimately blended together, and their debris then forms 

 only a single skin over the ripe seed. The nucleus 

 itself is sometimes exhausted in a similar manner; 

 whilst, in some cases, a deposition of nutritious matter 

 takes place within the tercine, and round the quartine 

 or embryonic sack. In some kinds of seed the nutri- 

 ment thus provided for the embryo is secreted within 

 the embryonic sack, and in others there is a secretion 

 of this description going on simultaneously within this 

 sack and the tercine also. In many cases this nutri- 

 ment, or " amnios," as it is styled in its earlier state, 

 Is not wholly absorbed by the ripening ovule; and it 

 ultimately becomes the ' ' albumen" or " perisperm" of 

 the seed, and is then farinaceous, hard, or oily. This 

 superabundant supply of albumen is of further ser- 

 vice to the embryo during its germination, and supplies 

 it with nutriment in the early stages of its develop- 

 ment, before the roots have sufficiently enlarged to 



