SUPPLEMENT 



29 



chemical bodies, not even SCHUNCK'S phylloxanthin and phyllocyanin, which 

 are relatively well characterized. On the other hand, one other by-product, 

 phylloporphyrin, has apparently been separated out in the pure state, and this 

 substance, 



I. 21, after to perform, read We cannot enter into a discussion here as 

 to the pigments of the variously coloured chloroplasts of red, brown, and 

 yellow Algae. 



110, 11. 1-3, for (HERTZOG . . . Bot. Ztg. 62, I, i], read (HERTZOG, 1902 ; 

 BERNARD, 1904, 1905 ; MOLISCH, 1904). Further, the statements of BACH 

 (1898) as well as those of USHER and PRIESTLEY (1906) to the effect that 

 a reduction of carbon-dioxide can be induced by the action of uranium salts 

 with the co-operation of sunlight, still await confirmation ; EULER (1904) was 

 unable to obtain any such result. 



II. 10-11, for to our eyes . . . purpose, read which is still strong enough for 

 one to see by. 



11. 14-16, for intensity of the light. We must first . . . what substances 

 read intensity of the light ; then only will it be possible to estimate the exact 

 significance of light in carbon dioxide assimilation. On the other hand, we 

 have still to inquire in the present relation what substances 



11. 41-52, for The variations from . . . beyond all doubt, read Indeed the 

 development of carbohydrate in the process of carbon -dioxide assimilation in 

 the green plant has been definitely observed. The necessity for the presence 

 of water in this constructive process has, however, as yet been shown only 

 indirectly. THEO. DE SAUSSURE (1804, p. 226) noticed that the increase in 

 dry weight of the green plant was considerably greater than could be accounted 

 for by the addition of carbon only, and this excess in dry weight must be due 

 to combined water. 



111, 1. 12, for iodine-proof read iodine-test 



11. 16-30, for When leaves . . . Orchidaceae. read By using a leaf freed 

 from starch it may be demonstrated very conveniently that it is only in light 

 that this process takes place, and that, too, only in regions immediately exposed 

 to it. It is sufficient to shade a part of the leaf by a piece of paper, cork, or 

 something of that sort, when afterwards this region, i.e. where no starch has 

 been formed, stands out clear on a dark background. Conversely, one may 

 cover a leaf with an opaque stencil, from which has been cut out, say, the 

 word ' starch '. After the leaf has been sufficiently illuminated, and after 

 treatment with iodine, the letters will appear black on an otherwise colourless 

 leaf surface. If we experiment with different species of plants we at once see 

 that very variable amounts of starch are formed in the same time, and that not 

 infrequently these amounts are the same for whole families. Thus, for example 

 (A. MEYER, 1885), a large amount of starch is formed in Solanaceae and Papi- 

 lionaceae, a considerable amount in Papaveraceae, Crassulaceae, Boragi- 

 naceae, Labiatae, &c., while only a little is formed in many Gentianaceae and 

 Iridaceae, and none at all in Asclepias Cornuti, Allium, Scilla, and other Lilia- 

 ceae and Amaryllidaceae. 



1. 48, delete appearing 



1. 49, for substances read sugars 



1. 55 P. 112, 1. i, for starch. [According . . . starch] read starch, and 

 hence we may speak of ' amyliferous leaves ' and 'sacchariferous leaves '. 



112, 1. 19, for from which the starch is formed read which leads to the 

 formation of starch 



1. 46 P. 113, 1. 4, for An optically inactive . . . (H 2 CO 3 ). read The analogy 



