298 



BOTANICAL GAZETTE 



[APRIL 



salts N/20, N/200, and N/iooo. Germination began 4 days after 

 the cultures were placed at room temperature and continued for 

 18 days. At the end of that time in practically all of the cultures, 

 in addition to the seeds which had germinated, others were found 



TABLE X 



Sambucus seeds in dilutions of acids, bases, and salts; 



TEMPERATURE 4-23° C. 



Substance 



Distilled water. 

 Distilled water. 

 Distilled water. 

 Distilled water. 

 Acetic acid. . . . 

 Acetic acid. . . . 

 Malic acid .... 



NH4OH 



NaOH 



NaOH 



(NH4)2S04.... 

 (NHJ.SO^.... 



ZnSO^ 



KNO,, 



NaNOi 



NaNOj 



C0NO3 



KCNS 



Normality of 

 solution 



N/200 



N/400 



N/400 



N/2500 



N/iooo 



N/2500 



N/20 



N/200 



N/20 



N/200 



N/20 



N/200 



N/200 



N/200 



Number 

 of seeds 



78 



8S 

 68 



83 

 79 



72 



75 

 77 

 88 

 70 



75 

 67 



50 

 80 

 46 

 72 



59 

 66 



Percentage 

 of 

 germina- 

 tion 



12 

 10 

 10 



13 

 18 



28 



15 

 18 



19 



17 

 28 



15 

 22 



30 

 19 

 30 

 71 

 31 



with the seed coat ruptured, but showing no sign of growth. All 

 cultures in which a forcing effect of the solution is indicated by the 

 germination of 20 per cent or more of the seeds are listed in 

 table XI. 



Out of 13 other substances not given in the table, 5 showed 

 results equal to or better than the average of the checks in at least 

 one dilution. The nitrates and sulphates are again found among 

 the more effective substances. So far as the nitrogen compounds 

 are concerned, these results agree with those of Gassner (10) for 

 seeds of Chloris ciliata. 



Potassium nitrate, mercuric chloride, and potassium iodide used 

 in connection with alternating temperatures had even less forcing 

 effect than the substances given in table XI. The concentrations 

 used were for potassium nitrate N/20, N/ioo, N/200, N/500, 



