538 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. LX. 



mixture of (modified) chlorophyll-green and xanthophyll. 

 Schunck (15) allowed the hot alcoholic extract to stand 

 until both the lipochrome and chlorophyll-green were 

 precipitated, and then rejected the pale filtrate with its 

 contained xanthophyll, and proceeded to separate the 

 lipochrome and chlorophyll-green. This he did by treating 

 the precipitate with a solution of caustic soda in boiliug 

 alcohol, which he says dissolves only the chlorophyll-green. 

 The remaining lipochrome was purified by successive 

 crystallisation from chloroform, and by treatment with 

 hot glacial acetic acid to remove fatty impurities. This 

 substance is the erythrophyll or chrysophyll of many 

 authors, is said by Arnaud (1) to be indentical with carotin, 

 and when pure forms crystals of " orange-red colour and 

 golden lustre " (Schunck). It is very readily destroyed by 

 light, is much more readily dissolved by benzol or chloro- 

 form than by alcohol, and gives a spectrum of two bands 

 in the blue region. Although this substance can be so 

 readily obtained from green leaves, there is some doubt 

 as to whether it actually exists as such in the leaves, 

 or whether it is not formed during the process of extrac- 

 tion. Schunck (14) opposes the theory of its existence 

 on account of the absence of its bands in the ordinary 

 spectrum of chlorophyll. For a converse reason he 

 considers that it is present in some autumnal leaves. 

 As, however, the spectrum of the same lipochrome 

 frequently differs considerably according to the solvent 

 used, conclusions based on isolated spectroscopic observa- 

 tions are not of very great value. 



The lipochromes of autumnal leaves are apparently the 

 same as those of green leaves, and do not therefore require 

 separate consideration. The removal or destruction of the 

 true chlorophyll in such leaves allows the lipochromes to 

 become visible, and their slow modification gives rise to 

 manv of the brilliant tints of autumn. 



FLOWERS AND FRUITS. 



The lipochromes of flowers and fruits arrange themselves 

 in two series, which apparently correspond to the xantho- 

 phyll and erythrophyll of leaves. The red and yellow 



