SUPPLEMENT 131 



whole internal pressure is devoted to the performance of external work ; in 

 many cases, as the external resistance increases, not only does the cell-wall 

 go on relaxing, but a rise in osmotic pressure over the normal also may 

 arise. 



11. 42-3, for imbibition water read water-content 



424, 1. 9, for it read the peduncle 



426, 1. 51, for 1877 read 1862 



427, 1. 43, after organ read (Statements of another nature made by HART 

 in the Botanical Gazette, vol. XXII, p. 505, appear to us, after an examina- 

 tion of several species of Catasetum in the Strassburg Gardens, to be erroneous.) 



429. Lecture XXXIV is XXXIII of the 2nd German Edition. 



11. 42-4, for if the lie ... suspended read the operation of gravity would 

 become suspended by constant and rapid change of the position of the ger- 

 minating seed, and that it might be counteracted by the agency of centrifugal 

 force. 



431, 1. 18, after Cordyline, read plumules of many Liliaceae, 



11. 27-8, delete and in unicellular . . . Phy corny ces. 



1. 29, after at all. read Finally one part of a cell may react geotropically, 

 while another part does not ; thus the sporangiophores of Mucorinae are 

 negatively geotropic, while the remainder of the mycelia of these Fungi does 

 not react to gravity. 



I. 35, after both ways, read at least in multicellular structures, 



II. 42-3, delete Almost all ... SACHS. 



433, 11. 14-31, for In order to ... in the middle line] read In all probability 

 the second alternative is the correct explanation, and the growth of the axis 

 remains unaltered. The question is not decided, however, because the intensity 

 of growth is so different in different individuals (LuxBURG, 1905). 



11. 51-2, for and for other . . . later on. read Every geotropic curvature 

 is neutralized, however, on the klinostat also, and this, as VOCHTING (1882) 

 has shown, is the result of so-called ' autotropism '. This autotropism makes 

 itself evident after every curvature and after every vigorous mechanical bend- 

 ing in such a way that the concave side is stimulated to more energetic growth ; 

 as a consequence the organ straightens itself, unless growth has during the 

 initial curvature come to an end. Autotropic curvature takes place, however, 

 not merely if the geotropic stimulus is eliminated on a klinostat, but when 

 gravity continues to act ; in the latter case, however, it leads to a flattening of the 

 curvature which has arisen, and not to complete neutralization of it (compare 

 also BARANETSKY, 1901). 



434, 11. 3-32, for In order that . . . growth occurs] read According to Count 

 LUXBURG'S (1905) measurements, geotropic curvature is brought about in 

 stems also by decreased growth on the concave side, without any alteration 

 of growth in the axis. This statement, however, is not of universal applica- 

 tion ; the joint-like swellings seen on stems or at the leaf bases of many plants 

 (Tradescantia, Dianthus, grasses) exhibit, on the contrary, a markedly increased 

 rate of growth in the axes after geotropic stimulation. 



435, 11. 40-2, for More recently . . . geotropic stimulus read With the nodes 

 of Gramineae which are in reality leaf bases are associated a whole series 

 of cushion-like thickenings occurring at the basis or apex of petioles ; all of 

 which retain the power of growth for a longer time than the adjacent stalk 



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