224 



Pliysiolotjical P re-<1etey tninatlo n 



Table I (after Wollny). 



Experimenl I (1874). 



Pea seedlings from entire seeds compared after 30 days with those from seeds from 

 which one cotyledon had been removed. The seedlingswerc provided with nutrient 

 solutions. Six seedUngs in eaoh experiment. 



P^ntire seeds 



Average weight of the aerial parts of the 



plants 

 Average weight of the roots... 

 Average breadth of the main root ... 

 Average length of tiie j)lants 

 Average breadth of the internodes 



^weight of a single 

 seed = 0-405 gm.) 



2-380 gm. 



0-872 gm. 

 118 units* 

 35-16 em. 

 185 units* 



Treated seeds 

 (weight =0-202 gm. 



l-207gm. 

 0-403 gm. 

 108 units* 

 29-63 cm. 

 151 units* 



Experiment II (1875). 



Pea seedlings from entire seeds, seeds with -^, and seeds with § of their cotyledons 

 removed, compared after 4 weeks. The seedlings were provided with nutrient 

 solutions. Four scedUngs in each experiment. 



Entire seeds 

 (weight of a single Seeds with Seeds with 



seed = 0-405 gm.) ^cotyledons | cotyledons 



Average weight of the aerial 

 parts of the plants ... 



Average weight of the roots... 



Average length of the plants... 



Average breadth of the inter- 

 nodes 



3-423 gm. 

 1-205 gm. 

 51-9 cm. 



168 units* 



2-016 gm. 

 0-679 gm. 

 43-7 cm. 



146 units* 



1-209 gm. 

 0-635 gm. 

 33-8 em. 



127 units* 



1 unit =0-01428 mm. 



Wollny subsequently conducted experiments with peas, vetches and 

 winter rye in which the development of the plants, which were grown 

 in soil under ordinary conditions, was followed through its ivhole course. 

 The results obtained from entire seeds were compared with those ob- 

 tained from seeds from which ^ and | of the cotyledons or endosperm 

 had been removed. These results are given in Table II. 



The total yield was very much larger in the case where entire seeds 

 were used than in the case of seeds with | cotyledons or endosperm, 

 and likewise very much larger again in the case of seeds with § cotyledons 

 or endosperm than in the case of seeds with only J of their food-reserves 

 available; but in contrast to the results obtained from the short-period 

 experiments, the ratio of the final yields was not the same as the ratio 

 of the atnounts of initial food-reserves. The yield relative to the amount 

 of reserve-material originally ])rosent was greater where the original food- 

 reserve was small (see column X in Table II). Wollny (I.e.) sumnuuises 



