128 VEGETABLK LIFE AND WORK, [SECTION 16. 



Accumlent, that is, the edges of the flat cotyledons lie against the radicle, 

 as in rig. 425, 436. In another they are 



or with the plane of the cotyledons brought up in the opposite 

 direction, so that the back of one of them lies against 

 the radicle, as shown in Fig. 427, 428. 



391. As to the situation of the embryo with respect 

 to the albumen of the seed, when this is present in any 

 quantity, the embryo may be Axih, that is occupying 

 the axis or centre, either for most of its length, as in 

 Violet (Fig. 429), Barberry Wg. 48), and ^5?=^ 

 Piae (Fig. 56) ; and in tliese it is straight. « / \\ 



But it may be variously curved or coiled 

 in the albumen, as in Helianthemum 

 (Fig. 430), in a Potato-seed (Fig. 50), 

 or Onion-seed (Fig. 60), and Linden 

 (Fig. 414) ; or it may be coiled around 429 430 



the outside of the albumen, partly or into a circle, as in Chickweed (Fig. 

 431, 432) and in Mirabilis (Fig. 52). The latter mode prevails in Campylo- 

 tropous seeds. In the cereal grains, such as Indian 

 iiAy Com (Fig. 67) and Ilice, 430 «), and iu all other 

 j,ljl^^' Grasses, the embryo is straight and applied to the 

 "isT 432 outside of the abundant albumen. 



392. The matured seed, with embryo ready to germinate and reproduce 

 the kind, completes the cycle of the vegetable life in a phanerogamous 

 plant, the account of which began with the seed and seedling- 



Section XVI. VEGETABLE LIFE AND "WORK. 



393. The following simple outlines of the anatomy and physiology 01 

 plants (3) are added to the preceding structural part for the better prepar- 

 ation of students in descriptive and systematic botany ; also to give to all 

 learners some general idea of the life, growth, intimate structure, and action 

 of the beings which compose so large a part of organic nature. Those who 

 would extend and verify the facts and principles here outlined will use the 

 Physiological Botany of the " Botanical Text Book," by Professor Goodale, 

 or some similar book. 



ElQ. 427. Seed of a Sisymbrium, cut across to show the incumbent cotyledons. 

 428. Embryo of the same, detached whole. 



Fig. 429. Section of seed of Violet ; anatropous with straight axile embryo in 

 the albumen. 430. Section of seeii of Rock Rose, Helianthemum Canadense ; 

 orthotropous, with curved embryo in the albumen. 430". Section of a grain of 

 Rice, lengthwise, showing the embryo outside the albumen, which forms the 

 principal bulk. 



FlQ. 431. Seed of a Chickweed, campylotropous. 432. Section of same, show 

 ing slender embryo coiled around the outside of the albumen of the kernel. 



