THE COLORS OF FLOWERS. 837 



structures now special to a higher group, that of the cuttle-fishes. 

 The bald and contemptuous negation of these facts by Haeckel and 

 other biologists does not tend to give geologists much confidence in 

 their dicta. 



THE COLOKS OF FLOWEKS. 



By AUGUST VOGEL. 



WHEN we contemplate the extraordinary diversity of colors of- 

 fered to us by the numberless flowers and fruits, ranging 

 through all possible gradations from the purest white to the most 

 intense black, we can do no less than admire so surprising a wealth 

 of color-shades, and are naturally prompted to imagine that chemi- 

 cal processes influence their tone and effect the manifold changes. 

 Although we are able to pursue the chemical processes occasioning 

 changes of color in the mineral kingdom we know, for instance, those 

 occurring during the conversion of the white color of silver chloride 

 into black those in the living plant, whereby equally striking changes 

 are effected, are unfortunately hidden from our scrutiny. For instance, 

 we do not know the process which causes the immature fruit of the 

 prune-tree to pass from the brightest of green, through the most vary- 

 ing gradations of color into light red, and finally deep dark blue ; al- 

 though we know that during the process of maturing the percentage of 

 starch is by the aid of the vegetable acids of the fruit gradually con- 

 verted into sugar, still, this phenomenon is not sufficient to throw light 

 on so extraordinary an alteration of hues. To the operation of light is 

 ascribed an essential influence in determining the vegetable colors ; but 

 that vegetable pigments can also be produced without light is shown 

 by the yellow turnips, carrots, alkanet-roots and other roots, all of which 

 develop their colors within the soil. Not only the light in general, but 

 also its volume, appear to exert an influence upon the intensity of these 

 pigments and their hues. This fact is confirmed by the intense and 

 lively colors of flowers blossoming upon high mountains, and the in- 

 crease of the flower pigment of the same species of plants with the 

 augmenting elevation, with otherwise the same properties of soil and 

 location. This increase of the pigments, such as is observed upon the 

 Alps and other high mountains, stands most assuredly in connection 

 with the stronger sun radiation at great height. It has further been 

 proved that, under the influence of the almost uninterrupted duration 

 of light during the short Scandinavian summer, many garden flowers 

 of Central Europe gradually increase in intensity after having been 

 acclimatized in Norway. Imported seeds of winter wheat, corn, peas, 

 and beans, grow darker from year to year, until they have finally as- 

 sumed the hue of native productions. Not alone do flowers, seeds, 



