— 245 — 



\ Tn n»/"* f oti An tllYl û 



V egGXdtlOIl llllitî 



Number 

 of plants 



100 seeds 

 dry matter 



Dry weight 

 of 100 plants 



Percent 

 production 

 of matter 



lDecbr.-20Decbr.. . 



15 



0.5 g 



0.61 



1.05 



22 Decbr.— 15January 



12 





0.68 



1.30 



21 January— 14 Febr. 



5 





0.68 



1.30 



19 Febr.— 14 March . . 



4 





1.10 



3.50 



21 March-20 April . . 



6 





4.43 



7.50 



24 April— 22 May .... 



1 





37.60 



16.70 



5 June — 27 June .... 



2 





22.10 



18.80 



Only the cotyledons 

 expanded 



4 — 6 leaves expanded 

 \ The exp. was finished at the 

 / beginning of flowering 



The points are plotted in the curve fig. 5. 

 The percent production of matter, calculated, is in July 16.5 % 

 The percent production of matter, directly estimated, is in June 

 18.8 %. 



The agreement between the two figures is very satisfactory. 



We will now compare these results with those obtained by 

 other investigators. 



Weber tried to estimate the C0 2 assimilation in the manner 

 described above (page 222). From his figures we can also calculate 

 the percent production of matter: 



Plant 



Vegetation 

 time 



Dry matter 

 at the be- 

 ginning of 



the experi- 

 ment 



Dry matter 

 at the ter- 

 mination of 

 the exp. 



Percent 

 production 

 of dry mat- 

 ter per day 



Tropæolum maj us I 



» » II.... 



50 

 50 



0.052 

 0.052 



9.090 

 8.957 



} 10.9 °/o 



Phaseolus multiflorus . . . 



48 



0.376 



6.212 



6.0 °/o 



» » .... 



48 



0.376 



9.279 



6.9 °/o 



Ricinus communis 



49 



0.128 



20.546 



10.9 °/o 





43 



0.093 



29.899 



14.4 °/o 





In a paper by Hornberger (1885 p. 415) the production of 

 dry matter in S inap is is dealt with. The seeds were sowed on April 

 24. Presuming that the germination lasted 6 days we can reckon 

 that the production of matter began on May 1. 



The content of dry matter per 100 plants was on May 26, 

 12.5 g and on the June 2, 41.1 g. Hence it can be calculated that 

 the percent production of matter per day was 13.2 and 14.3. (In 



