EFFECTS ON PLANTS 3 



tion — such as heat, light, atmospheric pressure, humidity, gravitation, and the 

 supply of nutrient material — exerts an influence upon plant growth, and conse- 

 quently upon both external form and internal structure." 



As to the duration of starvation, Coupin ('21) observed that seedlings, which 

 after germination were kept in distilled water in the dark, lived the following 

 number of days before death from inanition: nut-bearing pine, 60; pumpkin, 46; 

 winter vetches, 44; lentils, 40; marvel of Peru, 39; peas, 33; beans, 32; sunflower, 

 30; buckwheat, 25; radish, 24; nasturtium, 23; spinach, 22; tomato, 21; beet, 20; 

 common cress, 18; mustard, 18. Thus considerable variation occurs, which is 

 ascribed by Coupin to variations in the resistance of the plant itself, and espe- 

 cially to the quantity and quality of the reserve material available. London 

 ('97) found that active bacteria may survive without food for 49 to 88 

 days. 



As to the effect on size, it is well known that a decrease in size (or a stunted 

 growth) is the general effect of insufficient nutriment in plants; but the result is 

 usually less obvious than in animals on account of the rigidity of the cell walls 

 in plants. Quantitative studies on this topic in plants appear scarce. London 

 ('97) used a centrifuge in measuring the volume of bacteria {Bacillus anthracis, 

 B. subtilis and Streptococcus pyogenes), and found during inanition a progressive 

 loss amounting to an average total of 51 per cent (range 27-72 per cent). Some 

 measurements of retardation in weight of plants in the absence of certain growth- 

 promoting substances (vitamins) were made by Bottomley ('14). 



According to Winkler ('13), the dwarfing (nanism) due to inanition does not 

 always reduce the plant organism proportionately in all parts, but morpho- 

 logical peculiarities may occur (Gauchery, Kraus). Such modifications are 

 generally not hereditary, although de Vries ('00) obtained inheritance of 

 experimentally produced variations in Papaver sommiferum polycephalum. 

 According to Thomson ('88) and Rignano ('11), Hoffmann's ('87) researches 

 prove the inheritance of variations (such as relatively large number of atypical 

 flowers) produced by insufficient nourishment in Papaver, Migella and 

 Argemone. Inflorescence may also occur prematurely (Winkler) or in great 

 profusion (Gagnespan '19) as a result of starvation. 



Another effect of inanition upon the reproductive mechanism is possibly 

 the modification of sex (extensive review of earlier literature by Strassburger 

 '00, and 0. Schultze '03). Various botanists have claimed that the prothallia 

 of ferns grown under unfavorable nutritive conditions produce only antheridia 

 (male organs) , and no archegonia (female organs) . A suppression of the develop- 

 ment of female organs by malnutrition was observed in maize (Zea mays) 

 by K. Muller ('64) and Cugini ('80); and in Equisetum by Buchtien ('87) and 

 others. The relation of inanition to maleness is discussed by Hoffmann ('85). 

 Heyer ('84) was skeptical as to the modification of sex in Mercurialis by environ- 

 mental factors, though Klebs ('95, '96, '03) obtained positive results in some 

 Algae and Fungi. According to Geddes and Thomson ('01) : " The experiments 

 of Klebs may perhaps be regarded without unfairness as marking the real begin- 

 ning of a physiology of reproduction in plants. For he has set himself to show how 

 definite environmental conditions of nutrition, temperature, etc., are definitely 



