1918] AGRICULTURAL BOTANY. 127 



The viability of radish seeds (Raphanus sativus) as affected by high tem- 

 peratures and water content, H. D. Waggoneb {Amer. Jour. Bot., If (1917), No. 

 5, pp. 299-313, fly. 1). — A study of seeds of R. sativus of several varieties is said 

 to have shown that the viability of the seeds at given temperatures is lowered 

 by a high initial water content of the seeds, and that, at a given water 

 content, viability is lowered by an increase of temperature. Seeds injured by 

 high water content or high temperature suffer retardation in germination, 

 which shows a direct relation to these readings. Radish seeds of equal initial 

 water content show very much greater resistance to heat in dry-corked flasks 

 than in water, and still greater in open dishes in ovens. The amount of water 

 absorbed or given up by the seeds during treatment appears to be the chief 

 determining factor as regards the development of resistance. Seeds heated in 

 water lose increasingly in dry weight with rise of temperature. 



The influence of light on the germination of the seed of varieties of Nico- 

 tiana tabacum, J. A. Homjng {Bui. Deli I'roefstat. Medan, No. 7 (1916), pp. 

 1-1^). — Having noted a statement by Raciborski (E. S. R., 12, p. 1050) to the 

 effect that tobacco seeds locally tested germinated very poorly, if at all, in dark- 

 ness, and one by Gassner (E. S. R., 35, p. 222) to the effect that the seeds of 

 A^. tabacum belong in the group of seeds which are insensible to light, the 

 author has tested many varieties. He has found that while seeds of Deli 

 tobacco kept in darkness can not germinate more than a small percentage, those 

 of some other varieties germinate in darkness as completely as in light (but 

 require a longer time). 



The results of tests with 51 samples representing widely separated regions 

 are tabulated. In darkness the types obtained from the Balkans and Asia 

 Minor germinated most quickly of all and gave the highest percentages. 

 The American types gave a low rate (none above 50 per cent) of germination 

 or none at all in darkness. Types from western and central Europe took an 

 intermediate position, except in one case. Only the seeds of N. quadrivalvis 

 agreed with the seeds of N. tabacum used by Gassner as regards behavior in 

 darkness. 



The growth of isolated plant embryos, G. D. Bucknee and J. H. Kastle 

 (Jour. Biol. Chem., 29 (1911), No. 2, pp. 209-213).— In experiments attempting 

 to nourish the Lima bean plant with different compounds, it was found that 

 glucose and other sugars produced growth, while starch and Hopkins' plant- 

 food solution caused no appreciable stimulation. Cotyledons which showed no 

 reducing sugars caused no growth, while those cotyledons with glucose added 

 gave a good growth. Cotyledons of beans that had germinated and contained 

 reducing sugars also supported growth in isolated embryos. It appears that 

 growth is obtainable when glucose or a carbohydrate giving a hexose on hydroly- 

 sis is present, but not in the absence of these substances. While the dry bean 

 does not contain the food necessary to the growth of its own embryo, the 

 green cotyledon of a germinated bean contains the food materials necessary 

 to normal growth. 



Observations on the chondriome in tulip flowers, A. Guillieemond (Compt, 

 Rend. Acad. Sci. [Paris], 164 (1911), No. 10, pp. 401-J,09).— The author states, 

 that he has found the tulip flower to be as well adapted to the study of chon- 

 driomes as that of Iris germanlca, previously utilized for this purpose (E. S. R., 

 35, p. 333). The tulip flower has been utilized to make very precise observa- 

 tions, which are said to confirm those previously made regarding the elabora- 

 tion of the xanthophyll pigment. 



Characters and alterations in the chondriomes of the epidermal cells of 

 the tulip flower, A. Guillieemond (Compt. Rend. Acad. Sci. IParis], 164 U^H), 



