SUPPLEMENT 95 



315, 1. 41, after plant, read More accurate investigations (GAUCHERY, 1899), 

 especially from the point of view of anatomy, have certainly shown that the 

 limited size of the branches is not due simply to dwarfing of all parts. 



I. 54, after 1903 read SCHONE, 1906. 



316, 11. 11-12, delete so that . . . concerned. 



II. 14-17, delete so that . . . conditions. 



11. 21-31, for After what ... to them read The position of these cardinal 

 points shows many specific differences. The maximum is very low in certain 

 anaerobes : e. g. o-ooi of an atmosphere for Bactridium butyricum; 0-003 atm. 

 for Clostridium butyricum ; o-oi atm. for Bacillus carbonis ; 0-2 atm. for sulphur- 

 bacteria; 0-7 atm. for thio-bacteria. In many facultative anaerobes and in 

 aerobes it may rise as high as 9 atm. (PoRODKO, 1904). Further, every 

 organism has its specific minimum, which, on the whole, lies higher for Mould 

 Fungi than for Bacteria ; in the case of Phycomices, for instance, it is 0-6 per 

 cent, of oxygen by volume. 



1. 37, after 1901-2). read The distance between the maximum and minimum 

 cardinal points is extraordinarily varied, and that distance by no means ex- 

 presses a mean minimum and a mean maximum. For instance, according to 

 PORODKO, facultative anaerobes are characterized by having their cardinal 

 points very far apart, whilst obligate anaerobes have them very close together. 

 In addition to specific differences, individual differences also show themselves 

 in the position of the maximum and minimum, and WUND (1906) has shown 

 that the different growth phenomena of the organism, such as spore formation, 

 germination, and growth itself, are dependent in different ways on oxygen. 



1. 52, after calcium, read As far as carbon-dioxide is concerned, it has been 

 proved (CHAPIN, 1902) that it retards growth in roots when present in a con- 

 centration of 5 per cent., but inhibits it only when 25 to 30 per cent, is reached. 

 The corresponding numbers for stems are : 15 per cent, and 20-25 per cent. 

 A small percentage increase of carbon-dioxide in the air decidedly assists the 

 development of green plants, and it is difficult to understand how BROWN 

 and ESCOMBE (1902) arrived at an opposite conclusion. In nature certainly 

 such an accumulation of CO 2 is not easily reached, since this gas is decom- 

 posed by green plants and so rendered harmless. 



317, 11. 38-41, for That chemical . . . stimuli read In the germination of 

 the seeds of aquatics also chemical stimuli play an important part (A. FISCHER, 

 1907). 



That chemical stimuli also act in a formative manner may be concluded 

 from the behaviour of Basidiobolus, a description of which has been given at 

 p. 248 : further examples of the same phenomenon will present themselves 

 when we come to discuss gall-formation. 



Among the other morphogenic effects of chemical stimuli we may note only 

 the facts that in a concentrated sugar solution Stichococcus produced cells far 

 more elongated than under natural conditions (ARTARI, 1904), and that 

 Spirogyra may be made to transform its normally cylindrical cells into barrel- 

 shapeds wellings (GERASSIMOFF, 1905). 



1. 51, after state read (comp. RABE, 1905). 



318, 11. 16-17, for by entry . . . follows read in many cases a reaction 

 may follow either by penetration of the external osmotic substance into the 

 cell, or by the new formation of osmotic substances therein, 



319, 11. 46-51, delete According to ... as it seems.] 



1. 56, after conditions, read Again, mere extension growth is in nature affected 

 by so many factors that the significance of a single one is often very difficult to 



