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. The water-balance of succulent plants. Desert plants; Plant ecology; Cactus. FORM-ALTERATIONS AND GROWTH OF CACTI. 13 narrower, so that the arc of contraction and expansion is shorter; and furthermore the ribs arch and close together at the apex of the stem, thus offering a mechanical obstruction to free movement. I 1905 June n n 120 no S 100 IV 90. 140 IX 130 N XI 1+0 XU 120 July Aag. 8 14 21 28 Sept. II 18 25 Oct. I 10 16 23 30 FlO. 7.—Cxirves constructed from measurements of six intervals, three in a northern and three in a southern furrow of sahuaro No. 13, at the following heights: II a
. The water-balance of succulent plants. Desert plants; Plant ecology; Cactus. FORM-ALTERATIONS AND GROWTH OF CACTI. 13 narrower, so that the arc of contraction and expansion is shorter; and furthermore the ribs arch and close together at the apex of the stem, thus offering a mechanical obstruction to free movement. I 1905 June n n 120 no S 100 IV 90. 140 IX 130 N XI 1+0 XU 120 July Aag. 8 14 21 28 Sept. II 18 25 Oct. I 10 16 23 30 FlO. 7.—Cxirves constructed from measurements of six intervals, three in a northern and three in a southern furrow of sahuaro No. 13, at the following heights: II and IX, II inches; IV and XI, 3 feet; V and XII, 3 feet 11 inches. June 27 to October 30, 1905. (For rainfall data see fig. 5.) EFFECTS OF INSOLATION. After the first winter's measurements it was stated that " a comparison of measurements from the north and south sides of the same plants shows that the contraction is greater on the south than on the north side and that, while the southern furrows may begin to expand earlier, the northern ones expand ; Further measurements have confirmed this state- ment for the winter, the only part of the year during which, at that time, observations had been made; but the summer records subsequently taken, though less complete, indicate that for a period during which there is greater insolation of the north side the reverse holds Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original MacDougal, Daniel Trembly, 1865-1958; Spalding, E. S. Washington, D. C. , Carnegie Institution of Washington
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcactus, bookyear1910