14 ACADEMIC BOTANY. 



branches ; its caulicle often bears the cotyledons above 

 ground (though sometimes, when they are very large and 

 fleshy, as in the Acorn and Buckeye, the cotyledons re- 

 main under ground) ; its plumule lengthens into a Gaulis, 

 or true upper stem, with true leaves and branches. We see 

 therefore in the embryo a miniature plant with root, stem, 

 and leaves whilst still in the seed and attached to the 

 mother-plant, — wonderfully developed above the spore in 

 Cryptogamia. 



26. The CoUum, or neck (Fig. 7, D, m), is the focus of 

 the two axes of the plant : the descending axis, which re- 

 gards the root and its functions ; and the ascending axis, 

 which regards the stem and its functions. These functions 

 are quite distinct, as we shall see, 



27. The Axis of Growth of the flower (13) is called the 

 Torus (L. cushion or couch). It segregates the generative 

 organs from the body of the plant; at the same time it 

 keeps them in communication with the plant, from which 

 it transmits nutriment to them. In Cryptogamia it is 

 often a mere line or point, as at the base of the organs in 

 Vaucheria (Fig. 1, A, B, C). In Phanerogamia it is often 

 conspicuous, forming a disk, as in the Vine (Fig. 4, l). 

 When the male and female flowers (stamens and pistils) 

 are on the same torus, as in the Vine, Cherry, Primrose, 

 etc., the flower is called Bisexual (two-sexed), and also 

 Monoclinous, or one-couched (Gr. Idine, couch). When the 

 male and female are on separate tori (plural of torus), as in 

 the Vaucheria (Fig. 1) and the Maize, or Indian Corn, the 

 flowers are Unisexual (one-sexed), and also Diclinous, or 

 two-couched. Diclinous floM'ers are called Dioecious, or 

 two-housed (Gr. oikos, house), when the male and female 

 are on separate plants, as in the Date, Willow, Hemp. 

 They are called Monoecious, or one-housed, when they 

 are on the same plant, but on separate tori, or couches, as 

 in the Vaucheria (Fig. 1) and Indian Corn. The place 

 which the stamens occupy on the torus is called the An- 

 drceoiiim, or man's house (Gr. andros, man); the place 

 occupied by the pistils is called the Gyncedum, or woman's 

 house (Gr. gyne, woman) ; and this is always in the centre 

 of the torus. The staminate flower is called Sterile, or bar- 



