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THE  STUDENTS   MANUAL

II. MORPHOLOGY.

1. THE CELL: the unit of structure   355.

a Cellulose: cell-wall 357.

b Protoplasm: the living substance of the cell 1554.

c Karyokinesis:  cell  division  993;   as  in  diatoms 527; and nostoe 492. (1) Meristem  or formative tissue  1207.

(1)     The     nucleus 1365.

(2)   The   cytoplasm

493.

2. THE SPORES: special cells for reproduction 1803.

b Asexual  spore:

— formed b y cell division 117.

c Sexual spore : formed by union of cells 1730.

a The Archesporium:    which  sets  apart   certain cells for reproduction 91.

(1) The sporangium: in

which the spores are formed 1803.

(2)   The  tetrad   forma-

tion:   four sister spores 1894.

(1)   The    gametes:    or

sexual cells 735.

(2)   The   antheridium:

or male organ 78.

(3)  The   archegonium:

or  female   organ 91.

(4)   The    sperm:     the

male cell 1796.

(5)   The oosphere:  the

female cell  1385.

(6) The oospore: or fer-

tilized  egg   1385.

3. ALTERNATION OF GENERATION:  55.

d, Heterospory: in which the gametes are unlike 871.

fa. Gametophytes: the generation producing sex-organs 55;  apogamy 83.

b. Sporophytes:  the generation producing asex-

ual spores 1804; apospory 83.

c. Homospory: in which the gametes are alike

883.

(1)  Microspores:     pro-

ducing male ga-metophyte 1221; microsporangium 1221.

(2)  Megaspores:     pro-

ducing a female g a m e t o p h y te 1199; megaspo-rangium 1199.

4. THE SEEDS:  which produce the flowering plants 1718.

(1) The testa: or hard coat upon which hairs and wings grow 1894.

{(a) Cotyledons: the first leaves developed 465. (b) Hypocotyl: the stem-like portion beneath 907.

(3) The   endosperm:    food  tissue  within   em-

bryosac 614.

(4) The perlsperm:  food tissue outside embry-

osac 1452.

2268

a. Parts of the seed: