THE FLOWER DEFINED.— THE EMBRYO. 



these cases the spores (Fig. 1, D) are provided with hairs 

 called dlixB (L. (Alia, hair), and are endued with self-motion. 

 They are therefore called Zoospores, or animal-spores. 



These little creatures are very social ; they dance among them- 

 selves, circling merrily, but never jostling; no human dancers could 

 he more polite ; then, when the heyda)' of youth is over, they with- 

 draw their cilise (Fig. 1, E), produce an outer wall, send out root-like 

 projections (Fig- 1, F), and develop into staid mother-plants. 



15 a. Waked and Covered Spores. — In the lower Crypto- 

 gamia — Seaweeds, etc. — the spores are naked ; that is, they 

 have no special cover immediately surrounding them. The 

 plants grow broadly from a common centre, without dis- 

 tinction of stem or leaf; they are called Thallogens (Gr. 

 thallus, a young shoot, gennao, to grow, beget), and may be 

 called Broad-growers. In the higher Cryptogamia — Ferns, 

 etc. — the spores are covered ; the plant-growth is upward, 

 from the top ; they are called Acrogens (Gr. akros, top, end, 

 summit), and may be styled Top-growers. 



16. Phanerogamia. — A. The female flower is called an 

 Ovule (L. ovulum, little egg) ; sometimes 

 called Nucleus, or kernel. It usually 

 has two coats (Fig. 3, a) called Seed- 

 coats. 



The inner coat is called Secundine, or sec- 

 ond coat (though it is first formed). The outer 

 is called Primine, or first coat. The opening 

 in the Secundine is called the Endosiome, or 6, 

 inner mouth (Gr. endon, .within, 

 stoma, mouth). The opening in the 

 primine is called the Exostome, or 

 outer mouth (Gr. exo, outside). The 

 apex of the a n « a 

 ovule (Fig. 3, B D a ^i 

 a, n) points to 

 these mouths. 

 The two coats 

 are attached 

 to the ovule 

 onlv at its base 

 (Fig. 3, A, 



en,) ; this point ohalaza. B, poUeu-Rrain emitting its tube. C, a, b, e, d, embryo (now 

 is called the become many-celled) at different stages of growth ; d, showing two 

 Chalaza f Gr cotyledons forming. The long thread-like part in the four figures is 

 tubercle) ; the *e.uspenBor. 

 orifice at the apex of the coats (whether there be one or two coats) 



Fig. 3. — a, ovule of Smiirtweed {Pol i/gonum), with two coats ; n, nu- 

 cleus ; », embryo-sac. A, pistil of same ; o, ovary ; Biyl, style ; aig, 

 ptigma ; p, pollen-grains ; tp, pollen-tube ; ve, embryonic vesicle ; c/i, 



