PART I 



PLANTS AND INVERTEBRATES 



CHAPTER I 



EFFECTS OF INANITION ON PLANTS 



While the present work is concerned chiefly with the effects of inanition 

 upon animals, a brief (and necessarily incomplete) review of the effects upon 

 plants also will be found of interest and value. The general observation that 

 plants, as well as animals, thrive according to the quantity and quality of 

 their nutriment was doubtless made even in prehistoric times. More exact 

 knowledge has slowly accumulated, but apparently the process of starvation 

 has been studied less extensively in plants than in animals. The metabolic 

 processes are fundamentally similar in plants and animals, and some aspects of 

 inanition (especially of partial inanition) are more clearly apparent in the 

 simpler plant organism. The chief effects of inanition on plants will first be 

 summarized briefly, followed by a more detailed account of the results of total or 

 partial inanition upon the various species. 



Summary of the Effects on Plants 



Plants in general, much more than animals, appear susceptible to modification 

 by various external factors, including the food supply. It is difficult to sum- 

 marize briefly the principal morphological effects of inanition upon plants, on 

 account of the wide range in the character of these organisms and the great 

 differences in their mode of nutrition. In general, however, it will appear that 

 the effect of inanition is to restrict or inhibit their growth during the develop- 

 mental period, often resulting in premature development with the production of 

 marked abnormalities of form and structure. In the poppy (Papaver) an inheri- 

 tance of some of the experimentally produced variations is claimed. In later 

 stages of growth the plants are usually less susceptible, but sooner or later a 

 deprivation of nutriment will usually produce protoplasmic atrophy, with pro- 

 gressively degenerative changes in the cells and tissues, finally resulting in 

 the death of the organism. Of the cell constituents, the formed storage prod- 

 ucts (starch, oil, etc.) are usually consumed first; then the cytoplasmic struc- 

 tures are attacked; lastly the nucleus, which is the most resistant. 



These effects are produced not only by general or total inanition (either com- 

 plete or incomplete) but also often in a strikingly characteristic manner by par- 

 tial inanition, when there is a marked deficiency of only one (or a few) of the 



