ICS STATE POMOLOGICAL SOCIETY. 



lake Oti several different forms, by using different parts as a scorehouse of food 

 for future use. 



In different plants we find nourishment stored away in parts which are com- 

 monly used for other purposes. The storehouse is in the leaves of the century 

 plant. In fruits and seeds, we find it now in the cotyledons of beans and peas, 

 in the albumen of buckwheat and corn, in the calyx of the apple and winter- 

 green berry, in the top of the flower-stalk in the strawberry, in flowers, leaves, 

 and stem of the pineapple. It looks to me as though there was some mysteri- 

 ous faculty or unknown quality in plants which we have not begun to under- 

 stands Cut off a branch covered with leaves and insert the top end in a liquid, 

 ft/jd the water goes freely in the opposite direction to its usual course. Trees 

 have been pulled up, the tops buried, and roots left in the air. In this invert- 

 ed condition, leaves and buds have grown from the roots in air, and roots have 

 grown on branches in the ground, the trunk serving as a medium either endup. 



Sap rises often when there are no leaves on the plant. The wood of the 

 maple is gorged with sap before the leaves are developed in spring, when the 

 entire surface of the trunk is covered with dry bark and bud-scales. Cut the 

 tree on a cold day and no sap comes forth ; cut the tree in bright, warm sun- 

 shine of March, and it flows rapidly. The latter phenomena are explained by 

 Bupposing that minute particles of air in the cells contract in the cold and ex- 

 pand by heat, forcing the sap to rise higher or escape from a wound in the 

 bark. The escape of water from the leaves is not necessary for the growth of 

 plants. They often grow most rapidly when the air is saturated with moisture, 

 as on rainy days, and when plants are confined in a AVardian case. 



Quite recently President Clarke and the rest of the Faculty of Massachusetts 

 Agricultural College, have made some very valuable experiments on the circu- 

 lation of sap in plants. I can here only refer to a few of them. Of the trees 

 or plants which produce a flow of sap when cut, "each species has its own 

 time of beginning," and running its course till it ceases for the time. 



Sap flows slower and with less force as we go up the tree. Some of Presi- 

 dent Clarke's experiments showed that a maple tree will run twice as much 

 eap when tapped on the north side. He has since found that, in most cases, 

 maples produce most sap when tapped on the south side. When sap is run- 

 ning insert a gauge in one side of a tree to indicate the pressure ; tap the other 

 side and immediately the gauge indicates a lower pressure. Closing the hole, 

 in ten minutes the gauge rose again to its former level, by re-absorption from 

 the roots. A tall maple tapped in the top did not flow a drop; half way down 

 the pressure was half as great as near the ground. 



A gauge in cold weather in spring indicated a suction equal to a 25.95 feet 

 of water: as the sun came out it changed till it represented a pressure of water 

 44 feet high. On May 4th a birch tree showed a pressure of water equal to 84.77 

 feet in height. A birch root, on April 30th, an inch in diameter, a foot under the 

 cold soil, shaded by trees and leaves and on the northern slope, lying in a 

 horizontal position, was cut oft* from the tree and a gauge attached to it. At 

 noon the gauge showed the enormous pressure of 85.80 leet of water. "This 

 wonderful result showed that the absorbing power of living birch rootlets, 

 without the aid of the numerous helps imposed upon them by ingenious 

 philosophers, such as osmose, exhalation, dilatation, contraction, oscillation, 

 capillarity, etc., etc., was r^uite sufficient to account for the most essential of 

 the curious phenomena connected with the circulation of the sap." 



"In conclusion," says President Clarke, "we may as well admit that life is 



