THE GROWTH OF A SEED 25 



mens are borne certain cells that open by valves, and which contain the male 

 element of the llower called the pollen. The central set of transformed 

 leaves makes what is called the pistil or female organ of the flower. At the 

 lower end of this grows the seed vessel, or ovary, containing the ovules, which 

 are to be transformed into seeds. At the upper end of the pistil is a variously 

 shaped organ known as the stigma, which is naked and for a while moist on 

 the surface. The pollen, or male element, falls on this and swells and begins 

 to grow into a tube of various lengths, according to the character of the 

 flower. This pollen tube passes through the tissue of the pistil till it reaches 

 the ovary, and there in a certain cell of the ovule it sets up a new growth of 

 cells, that gradually take on the form of a miniature plantlet, and form 

 what is called the embryo, or germ, of the seed. In this seed the plant then 

 stores up starch or oil sufficient for its sustenance till in its germination it 

 can make green leaves. It then rapidly parts with the water and the seed be- 

 comes ripe, and remains dormant until brought again under the influence 

 of moisture, warmth .and the oxygen of the air. 



A seed then is a living organism in which vitality is simply suspended 

 for a time, and which contains all the elements of a future plant when placed 

 under proper conditions for growth. If it has these conditions it will grow. 

 If they or any one of them are absent it will remain dormant or perish. If the 

 seed is buried so deeply that the oxygen of the air cannot properly affect it, 

 though there may be moisture and heat, it will not grow. We see this fre- 

 quently in the case of clover seeds deeply buried in the soil, which grow after 

 they have again been turned up to the influence of the air. If moisture is 

 absent, the living matter of the seed cannot swell and become active, and 

 though there may be heat and oxygen enough, the seed cannot grow. . Then, 

 too, there may be moisture and oxygen, but if the temperature is not right 

 for that particular seed, it will not grow. This proper temperature varies 

 with different seeds. All cultivators know that some seeds need more heat 

 than others. The garden pea will germinate at a temperature but little above 

 the freezing point, while Indian corn subjected to the same conditions will 

 perish. It is essential then, to know something of the nature of the seeds we 

 plant so that we may give them the proper conditions of growth. 



THE FRUIT. 



While the seed is the final result of the plant's effort at reproduction, 

 the fruit is the ripened vessel or ovary which contains these seeds. The pea 

 pod is the fruit of the pea plant, and is simply the ripened seed vessel. But 

 there are some plants in which other parts are commonly known as the fruit. 



