ANTHOCYANINS AND GENETICS 205 



pathological, and may quite well be responsible for the general weakness 

 of the variety. 



As to the connection between colour and other characters such as 

 flavour and odour, information is rather scanty. Some interesting 

 suggestions in this direction have been made by Goff (444). He main- 

 tains the truth of the statement that white varieties of fruits and 

 vegetables have a milder and more delicate flavour than coloured 

 forms, and he quotes the following instances. White varieties of 

 onions, he says, are less strong in flavour than red ones, the blood-red 

 variety being the strongest flavoured; white currants are less acid 

 than red or black; white and yellow tomatoes are sweeter than the 

 scarlet ; white raspberries have a more delicate flavour than the coloured 

 type. The same idea is involved in the blanching of celery, endive and 

 seakale, and in the use of the inner leaves only of lettuce and cabbage 

 for eating. Similarly, 'sun-burned' potatoes, that is tubers which have 

 been exposed to light and sun, have a strong and bitter flavour ; shoots 

 of seakale also, if allowed to come above the earth, develop purple 

 pigment and become strong flavoured. Red cabbage, when cooked, 

 is less mild and tender than the green varieties. In the sugar-pea, 

 too, the purple-flowered form has seeds spotted with brown which are 

 strongly flavoured when cooked. He also points out that the percentage 

 of sugar in the Beet increases as the percentage of colouring matter 

 decreases. Further data would be necessary before we could definitely 

 prove the truth of these suggestions, but what evidence we have is 

 certainly in their favour. For odour, flavour, astringency, bitterness, 

 etc., are essentially connected with aromatic compounds, as for instance 

 bitterness and astringency with the tannins, and we know that absence 

 of colour is in some cases, as in Antirrhinum, accompanied by the 

 absence of certain aromatic complexes. The subject is well worth 

 investigation, and now that cases of Mendelian segregation offer such 

 well-defined material, it should not be beyond the scope of the plant 

 chemist. Also, the possibility of a connection between colour and 

 sweetness is materially strengthened by the evidence, given in previous 

 chapters, of a relationship between pigmentation and sugar concen- 

 tration. Goff states, for instance, that the red-fleshed Peach is of little 

 value for eating purposes, and cases of this kind should offer suitable 

 material for research. 



There are certain relationships of a more precise nature between 

 colour and other plant characters which have come to light in Mendelian 

 investigations. One group of such relationships includes the phenomena 



