GERMINATION OF SEEDS. 603 



Experiments were also instituted to ascertain whether 

 dormant seeds respired ; air deprived of carbon-dioxide was 

 aspirated over peas and then through an aqueous solution 

 of barium-hydroxide for ten to fifteen days : no trace of 

 carbonate was formed. This is a further refutation of van 

 Tieghem's statements. 



The action of twenty-two salts on the ' vitality ' of 

 dormant grains of Triticum {vulgare ?) has been studied by 

 Bruttini ^ ; the grains were immersed for twenty-four 

 hours in i to 2 per cent, solutions : considerable difference 

 in inhibitory action resulted. 



Similar experiments have been made by Vandevelde,^ 

 who steeped seeds in various solutions for twenty-four hours 

 and then placed them to germinate. Every solution in- 

 fluenced germination. He intends to publish shortly an 

 extensive communication, embodying the results of his own 

 work and that of others. 



Mosso^ finds that alkaloids exert a narcotic or stimu- 

 lating action on germinating seeds according to the 

 concentration of the solution employed. Seeds were 

 germinated in solutions containing from o'ooooi to 2 per 

 cent, of the hydro-chlorates of morphine, nicotine, cocaine, 

 of the sulphates of strychnine and atropine, and of caffei'ne 

 salicylate. 



Retrospect. — Exigence of space forbids more than a 

 short critique of the more important questions raised 

 on comparison of the preceding pages. One point towers 

 above all others, namely, that of the ' latent life ' of 

 dormant seeds. Pictet has stated that no chemical action 

 occurs at - 100" C, and Dewar has undoubtedly shown 

 that it is unknown with one or two exceptions at from 

 - 182'' C. to - 192'' C. ; yet seeds kept for four consecutive 

 days at - 100' C. germinated, and still more such as had 

 been exposed to nearly - 200^" C. Further, Romanes, 

 Ewart and De Candolle have shown that seeds, that have 

 not respired for more or less long periods, retain ' vitality * 



^ A. Bruttini, Ann. Agron., 21, 1895, 542. 



'^A. J. J. Vandevelde, Chem. Centralb. 1897, p. 822. 



^U. Mosso, Attn. Agron. 21, 1895, 544. 



