170 STATE POMOLOGICAL SOCIETY. 



GYRATION OF SAP Ilf CELLS. 



In certain cells of many kinds of plants, under the microscope, the sap, with 

 floating granules, is seen to slowly pass around the sides of the cell like an un- 

 easy animal trying to escape from a yard. No satisfactory cause has been given 

 for this circulation. I have watched it for hours without perceiving that any 

 of the sap passed out or into the different cells. 



GERMINATION 



is called a growth in one sense. Seeds when moistened, exposed to the air and a 

 certain amount of heat, germinate. Some seeds will germinate near the freez- 

 ing point, while the most favorable temperature for growth of seeds of wheat 

 is 80°, corn and squash 93°, cocoanut 120*. The germinating seeds assimilate 

 nothing for a while, but live on matter within or next to the embryo, matter 

 which was deposited there by the parent plant. By the time this is used up, 

 like the chickens just hatched, they are ready to go alone, and begin to work 

 for themselves. Sprouting of potatoes in spring in the cellar is a growth which 

 takes place at the expense of food stored up the year before. 



Plants need a season of rest from growth. If a lilac or rosebush, or apple 

 tree, or grape vine, be watered and warmed and fed continually, it will become 

 diseased and die in a few years. That plants have a season of rest is often if 

 not always true the world over. Flowering, and especially seeding, is an ex- 

 haustive process to all plants. If not allowed to flower or produce seeds, they 

 will become stronger and less inclined to die. Mignonette and many other 

 annuals so treated will become perennials. 



All the higher plants produce seeds after a process of 



FERTILIZATION. 



There are occasionally exceptions for a generation or two, but probably not 

 for many years. In almost all the lower plants, — the ferns, the mosses and 

 lichens on the old logs, rocks and fences, the shining green water plants of the 

 frog pond, the rust, smut, mildew and mould (which are plants), have nearly 

 all been found to have something answering to stamens and pistils, or some 

 kind of fertilization. 



Some low water plants occasionally come in contact with each other; the 

 contents of two separate cells meet and make only one new cell; this grows 

 and branches by division for a time, when the conjugation of cells again occurs. 



Desmids (water plants of single cells, found in our ponds) grow by division. 

 They also produce spores, answering to seeds, but occasionally — once a year, 

 perhaps — comes this blending of two cells to make one, called a kind of fer- 

 tilization. 



MODES OF FERTILIZATION IN HIGHER PLANTS. 



Intimately connected with this subject of plant growth is that of the man- 

 ner in which this is brought about in different plants. 



One of our plants, smilax, has such a stinking odor that blow flies lay their 

 eggs on it, probably deceived, thinking it to be carrion. In this visit the fly 

 carries the pollen from flower to flower. The agency of wind and insects in 

 fertilizing plants is a fascinating subject for two long lectures. 



Flowers are furnished with nectar and gay colors to attract insects, which 

 are well paid for their visits. The ingenious contrivances by which insects are 

 made to serve plants in crossing them is wonderful. "Where free lunches are 



