332 



Scientific Proceedings, Royal Dublin Society. 



The epidermal cells gave a dark colour with ferric chloride in almost 

 every instance. This may in some cases extend into the next deeper layer. 

 That this reaction is not due to tannin is shown by the fact that the con- 

 firmatory test with potassium ferrocyanide and ammonia always failed to 

 give a positive reaction. 



None of the sections darkened a tyrosine solution, either before or after 

 treatment with hydrogen cyanide. Consequently tyrosinase must be absent. 



The Plastid Pigments of Capsicum Fruits. 



In order to distinguish the chocolate from the red pigment, and to 

 ascertain whether they were mixtures, an examination was made of their 

 behaviour towards various organic solvents. 



The results are tabulated beside those for lycopin, carotin, and 

 xanthophyll as given by Willstatter and Escher (1910). From, the resem- 

 blance of the red of Capsicum to that of tomato, it was at first thought that 

 the colour was due to lycopin. The two fruits are, however, different shades 

 of red, and lycopin occurs not in plastids, but as crystals in the cell-sap or 

 in the cytoplasm. 



Table of Solubilities. 



' Pyridine was tried as a solvent for carotin, and it gave a deep-brown solution from which glitter- 

 ing orange crystals of carotin separate on cooling slightly. These are never acicular, but are exactly 

 like those figured by Willstatter and Escher (loc. cit.) aa obtained from ether by crystallization. 



