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usually in largest amount at the termini of the branches, as in 

 flowers and terminal leaves, or in roots, or in both tops and roots. 

 Their occurrence in those portions of the plant, which are young 

 and growing, points to the conclusion that they are not to be dis- 

 regarded in the study of metabolic processes. Goebel holds a 

 similar view. He says that it is ' very probable'that the feature 

 of color which so often appears when the propagative organs are 

 being brought forth has some connection with definite metabolic 

 processes, although till now we cannot recognize what these are.' 



" 2. The distribution of the so-called flower color substances in 

 other parts of the plant than the flower also points to the same 

 conclusion, and that the part which they play in attracting insects 

 to flowers, is, if indeed they have any function of this kind, inci- 

 dental rather than fundamental. The fact that certain colored 

 flowers, as in the spruce and red maple of early spring, are pol- 

 linated by the wind, would tend to confirm this view. The food 

 in the nectar and pollen are no doubt sufficient attraction for 

 insects and other animals. 



" 3. The occurrence of chromoplastids in a reserve organ, as in 

 the tuberous root of the carrot, and the similar occurrence of 

 chromoplastids and of reserve starch in the petals of the butter- 

 cup, lead to the inference that the petal of the buttercup, like the 

 root of the carrot, has the function of storing nutrient material. 

 In each case cells containing chromoplasts rich in nitrogenous 

 substances are associated with cells containing reserve materials. 

 In the case of the carrot the reserve materials are utilized by the 

 plant of the second year, and in the case of the buttercup they 

 are utilized in the development of the akene. 



" 4. The feeding of plants with chemicals for the purpose of 

 controlling color, as certain iron, aluminum, potassium and other 

 salts as well as certain organic acids, has not so far, in the au- 

 thor's experiments with carnations, roses and violets produced 

 any marked changes in the colors of the flowers, only some 

 slight effects being noted which might be attributed to other 

 causes. Knowing that plants have a certain individuality and 

 certain inherent qualties or tendencies, other than negative re- 

 sults could hardly be expected. On the other hand, the plant 



