Plants in Health and Disease. 



Chapter 1. 



GENERAL FEATURES OF PLANT LIFE. 



Nutrition and propagation, vegetative and seed reproduction. 

 Annuals, biennials, and perennials. General account of vegeta- 

 tive organs. 



Gardeners being concerned in the cultivation of plants, 

 it is obviously important that they should be acquainted 

 with their structure and mode of life. They will find it 

 particularly useful to know in what ways plants respond 

 to their environment, for such knowledge will enable them 

 by varying their treatment to modify the development of 

 the plants they cultivate, to accelerate or retard their 

 growth and to ensure the production of a greater number of 

 flowers. The gardener's aim is not always the same. The 

 flower lover is anxious to obtain a wealth of bloom. The 

 allotment holder on the other hand, concerned in raising 

 vegetables, may desire well-developed leaves, roots or 

 tubers. It is important therefore that we should study 

 both the vegetative and the reproductive organs. 



The former are concerned mainly with nutrition, the 

 latter with the propagation of the plant. These two sets 

 of organs are often differently affected by external con- 

 ditions. A gardener knows that by over-stimulating the 



