5° 



BOTANICAL GAZETTE 



[JANUARY 



methylene, the basicity becomes reduced; and the substituted 

 acid can then be titrated with sodium hydrate as a measure 

 of protein hydrolysis. Titrations made on a second lot of seeds 

 according to the Sorensen method gave results similar to the 

 Van Slyke determinations. 



The growth in these seeds occurring before germination is very 

 meager. There is no morphological change in endosperm or 

 embryo, although the latter increased slightly in length. After 

 the appearance of sugar the hypocotyl exerts a forward pressure, 

 separating the sides of the swelling cap which forces the coat open. 

 At this moment the cap is under so much pressure that it is dis- 

 torted, and a sharp angle is formed between its end and sides. The 

 growth following this stage will be discussed later. 



TABLE XVII 



Respiration of seeds at different periods of development at 25 C. 



(7 cc. volume) 



Condition of seeds 



Dry 



After s days at s° C 

 After 30 days at 5° C 

 After 60 days at 5° C 

 After 90 days at 5° C. 

 After 100 days at 5 C 

 After 130 days at 5° C 



No. 



500 

 SO 

 10 

 10 

 10 

 10 

 10 



Green 

 weight 



1.250 

 0.125 

 0.030 

 0.027 

 0.028 

 0.028 

 0.099 



Days 



Percentage 

 CO, 



1. 18 

 3-iS 

 3.78 

 3.80 

 3 .80 

 4.10 

 9-30 



Percentage 



COi+O; 



20.82 

 20.39 

 20.82 

 20.70 



20.68 



20.00 

 20.56 



Percentage 

 Oa used 



• 57 



• 77 

 .98 

 .90 

 .90 

 .00 

 •74 



ca 

 o* 



0.76 

 0.84 

 0.94 

 0.97 

 9.97 

 0.68 



0.95 



Mgm. CO, 

 per hour 

 per gm. 



o . 00098 



0.1311 



0.218 



0.2352 



0.2354 



o. 2486 



0.4890 



Mgm. Oj 

 per hour 

 per gm. 



.0011 



• 1347 

 .1976 

 .2151 

 .2075 



• 3192 

 ■ 4398 



Table XVII gives the results of the respiration experiments 

 obtained by the use of the Bonnier and Mangin apparatus. There 

 was a great increase in the respiratory intensity during the first 

 5 days and after the seeds split open. These are the periods when 

 the seed increased in water content. There was a very slow increase 

 in the respiratory intensity during after-ripening, even though the 

 water content decreased. The respiration quotient increased 

 very slightly during after-ripening, but decreased to a minimum 

 at germination. Not only does this low respiratory quotient of 

 o . 68 indicate the time of intense fat metabolism, but at this par- 

 ticular period it was found that the fats were being transformed 

 into carbohydrates. It would be interesting to know this quotient 

 at 5 C, as it would probably be much lower. After germination 



