JAMAICA. 



BULLETIN 



OF THE 



BOTANICAL DEPARTMENT. 



New Series.] FEBRUARY, 1901. * / " J 



J Part II. 



TWO OPPOSING FACTORS OF INCREASE. 



By Prof. J. C. Arthur.* 



The energies of the plant are used for two general purposes : the 

 development and maintenance of the vegetative parts, and the forma- 

 tion of special reproductive bodies. In some respects the efforts of 

 the plant in these two directions are antagonistic. The vegetative 

 part consists of root, stem, foliage, etc., and at first, and sometimes for 

 a long period in the life of the individual, the energies of the plant 

 are wholly absorbed in increasing the size and promoting the func- 

 tional activities of these organs, all being connected with the welfare 

 of the individual plant. After a time special reproductive structures 

 are developed, consisting of seeds or spores, and the accompanying 

 parts that aid in their protection and dissemination. They find their 

 use in continuing the race, that is, in providing for another genera- 

 tion of indivuals. 



The formation of the vegetative part and the formation of the fruit- 

 ing part may be treated as separate tendencies in plant life. They 

 Tarelv proceed pari passu, for usually if one is favoured, the other is 

 less favoured. This is popularly expressed by saying that the plant 

 runs to leaves, or runs to vine, or on the other hand that it runs to 

 seed, or it overbears. 



The portion of the plant having economic value for food belongs 

 sometimes to the vegetative, sometimes to the reproductive side. Most 

 fodders, and many culinary vegetables, such as cabbage, radish, let- 

 tuce, and asparagus, belong to the vegetative part, while the grains, 

 fruits, and such vegetables as peas, beans, tomatoes and egg plant, 

 belong to the reproductive side. The object of cultivation is to in- 

 crease the size and quality of the part used, and it is evident there- 

 fore, that one requirement of the husbandman must be to learn the 

 conditions which promote the development of the particular side of 

 the plant to which the crop in question belongs. 



* Reprinted f-om a most interesting collection of Essays entitled " Living 

 Plants and their Properties," by Professors J. C. Arthur and D. T. MacDougal, 

 published by Messrs. Baker & Taylor, New York. 



