196 Alf,*e<l J. Evmrt: 



Nolibe and Hanleini found that a large number of seeds, 

 although soaked, only germinated after long intervals of time (3 

 years in some cases), and considers that this is due to some 

 change taking place slowly in the embrj^o during rest. The 

 delay was, however, merelv due to the low temperature. All the 

 seeds in the list, when soaked, provided with oxygen and 

 kept at 25-30 deg. C, begin to germinate in 1-30 days after 

 absorbing water. Further, it is impossible to keep any of these 

 seeds at a suitable germination temperature (20-30 deg. C.) 

 without their decaying long before 3 years have elapsed. Even 

 if they are frequently washed, which does not appear to have 

 been done by the authors, in nearly all cases signs of decay can be 

 seen within a month of soaking if the temperature is above 

 20 deg. C, and usually before this. The fact that Nobbe and 

 Hanlein found 9 out of 31 seeds gave germination percentages 

 of nil or below 1 per cent, is sufficient to show that they did not 

 work under proper conditions, for the plaints mentioned are freely 

 seeding ones, and two of them, Verhascum ?iif/rmn a.nd PIanta(/o 

 major, gave percentages of 42 and 64 per cent, within 3 Aveeks 

 on germinating soaked seed at 25-30 deg. C 



Nobbe and Hanlein found that seeds of Chenopodium album 

 Hnd CheIido7iium ma jus mostly remained in the soil for 1 year, 

 and scune for 3 years before germinating. Here, again, all pro- 

 perly soaked seeds kept at 25-30 deg. C. and freely aerated, 

 germinate within a month, and by that time all the dead soaked 

 seeds are distinctly decayed. 



Vnirious observers have stated that seeds of Cucurhita and 

 Allium germinate more readily and abundantly after keeping a 

 year or more, or warming for a time, than when fresh. This 

 certainly does not apply to all samples, of seed, and hence it is 

 not easy to say whether we are dealing with a manifestation 

 of after ripening, or with some changes in the character of 

 the seed coats. In some of the seeds examined by Duvel the 

 fresh seed gave a lower percentage germination than the same 

 seed examined a year later ; but this may have been due to 

 imperfect methods. Such results as those for Larfura Scariola, 

 for instance, are obviously inaccurate, and in many cases Duvel 



1 Laiidw., Ver.siiclisst, 1877, p. 63, 1880, p. 4(i.'>. 



