BRIEFER ARTICLES 



LONGEVITY OF SEEDS £1 



In a recent article on longevity of seeds, Ewart 1 makes a number of 

 statements which merit comment. He assumes as correct the claim of 

 Bergtheil and Day 2 (working on Indigo/era arrecta) that they have 

 priority in discovering that the water-resisting power of the seeds of legumes 

 is due to the character of an outer layer of the coat. Nobbe,3 however, 

 pointed out the fact for Tri folium pratense 31 years before the publication 

 by Bergtheil and Day. Both find that stains dissolved in water penetrate 

 in the hard seeds only through the very thin outer layer, called cuticle by 

 Nobbe; but that they do not pass through the palisade layer. This is 

 shown in fig. j of Bergtheil and Day's article. Ewart finds the resist- 

 ance in Adansonia digitata to be due to the impermeable nature of all layers 

 of the integument, and I find the same to be true of the hard seed of Axyris 



amarantltoides. 



Legum 



meability to water is never due to oily deposits. I find 

 the mesquite (Prpsopis juliflora) is an exception. By soaking these seeds 

 in ether for several days and then allowing the ether to evaporate, a large 

 percentage is caused to germinate when germinative conditions are supplied, 

 WW e a direct supply of germinative conditions brings only 5 to 10 per cent, 

 he evaporation of the ether in which they have been steeped always shows 

 an oily residue. Absolute alcohol is less effective in this case. 



until 



germinate 



Crocker obtained no definite confirma- 



ion or negation of this fact, but here also it appears to be a case of the slow 

 ^integration of the seed coats." This is hardly consistent with the state- 



(p 



In this case, however, 



ave underestimated the significance of the coats. I find that in Cra- 



iaeg 



the t embr yos taken from apples just ripe and entirely freed from 



coats and endosperm begin growth within a few days after being 



T TT* 



Mc, T ' L '> ° n the longevity of seeds. Reprint Proc. Rov. Soc. Victoria 



n< b * 2I - PP- 210. inn* 



arrecta. 



ekgtheil, C, and Day, D. L., On cause of "hardness" in seeds of Indigofera 



^Annalsof Botany 2i: 57 _ 6o . I0o7 . 



obbe, R, Handbuch der Samenkunde 117. 1876. 

 42:a6-- 2 CKER ' ^ "'' R ° le of seed coats in delayed germination. Bot. Gazette 



69] 



[Botanical Gazette, vol. 47 



