176 LIVING PLANTS 



the flowers and fruits of the seedforming 

 plants. The lipochromes constitute the pig- 

 ments of many animals also. Examples in 

 the two groups are offered by the yellow color 

 of the yolk of a hen's egg, and by the reddish 

 3^ellow of the carrot, or the sulphur yellows 

 of certain fungi. These substances occur in 

 various forms, in oily drops in the fungi, in a 

 diffused state throughout the plasma in bac- 

 teria, and in crystalloids in the carrot and in 

 flowers. In leaves the lipochromes are sup- 

 posed to occur in the chloroplasts. If an 

 equal amount of kerosene or benzole is added 

 to a solution of chlorophyll in alcohol and the 

 mixture is shaken and allowed to stand for a 

 few hours, the alcohol containing a yellowish 

 lipochrome, xanthophyll, will separate from 

 the kerosene or benzole solution. The yel- 

 low and 3^ellow-red tints of au tumn leaves are 

 due to the lipochromes which become visible 

 after the decomposition of the chlorophyll. 



In leaves the lipochromes are supposed to 

 act as a screen in preventing the disintegrat- 

 ing action of light on nitrogenous substances. 

 Since the lipochromes disappear during the 

 germination of the spores of fungi it is sug- 

 gested that a function as reserve substance is 

 also subserved. Colored bacteria in which the 

 pigment is a lipochrome of which. Bacillus 

 brunneus, B. cinnbareus, Micrococcus agilis 



