THE HORTICULTURAL SOCIETY OF NEW YORK. 



the governing principle of drainage. Drainage is necessary to remove 

 water from the soil, so that the air can enter it and the chemical changes 

 of nature's laboratory be carried on there. Beside this requirement of 

 the proper amount of water and the mechanical condition of the soil, the 

 plant food contained by the soil is the next important consideration. This 

 plant food is both mineral and vegetable, and must be in a condition to be 

 dissolved in water before being taken up for the use of the plant. Besides 

 the soil, the other conditions, outside the plant itself, that the horticulturist 

 must consider, are the exposure to moisture, heat and light. The proper 

 requirement of moisture is of great importance, and the maintenance of a 

 proper degree of heat is equally important, while the exposure to light is 

 an absolute necessity for all green plants. 



The amount of light to which a plant is exposed has a great deal to do 

 with its best development, and it is an interesting fact that the light from 

 the sun, in greenhouses, can be supplemented by artificial light to great 

 advantage. In England, where the sunlight is much more limited than it 

 is in America, electric light is used to advantage on dark days or for 

 lengthening the light in the short days of winter. This is used both in 

 the development of flowers and in ripening of fruits in fruit houses. This 

 use of light is parallel with the use of artificial heat supplementing that 

 of the sun. 



Passing these external conditions of the plant we come to the plant 

 itself, and we must understand the processes of its growth, development 

 and reproduction. The plant may be reproduced from seed, or propagated 

 from buds, cuttings or layers, but the cuttings and layers are but other 

 forms of bud. propagation. The production of the seed involves the 

 infinite variety of flower formation and the operation of the sexual organs 

 they contain. At the verj' basis of plant cultivation lies the knowledge 

 of nature's method of reproduction by seed. Nowhere can we find more 

 wonderful organs than those contained in flowers for this purpose, and 

 nowhere can we find more interesting formations than those which regu- 

 late the fertilization of flowers by the agencies of wind or insects. In 

 the first place, it is a remarkable fact that, in plants that are not self-fertil- 

 izing, there is a great difference in the showiness of the flowers of those 

 that are fructified by the agency of wind or by insects. Those fructified 

 by the wind are almost always inconspicuous, while the marvellous display 

 of color and attractiveness of flowers is almost always among those where 

 bees and insects are necessary for the conveyance of the pollen of one 

 to another. 



Not less wonderful is the provision that nature makes in some flowers 

 to prevent self-pollenization and to provide for the bringing to the pistils 

 of the flowers the pollen from the stamens of some others. The most 

 striking of these are found in the orchid family. Among the most 

 curious of this varied flower structure is that of plants where, in some 

 flowers, the stamens and pistils of unequal length are so placed that only 

 a bee bringing pollen from the long stamen of one flower can reach the 



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