EEPKODUCTIVE ORGANS OF PLANTS. 341 



AbsoPute Weight of Commeralal Seeds. 



Number of Weight of one Seed in 



Samples Milligrams. 



Examined. Average. Maximum. Minimum. 



Oats 84 28.8 54.1 14.7 



Barley, 66 41.0 48.9 27.7 



Rye 119 23.3 47.9 la.O 



Wheat 95 37.6 46.8 15.2 



Maize, 22 282.7 382.9 114.6 



Beet 39 22.0 42.4 14.2 



Turnip, Brassica rapif era,.. 23 2.2 3.0 1.4 



Carrot 36 1.2 1.7 0.8 



Pea 43 185.8 584.6 46.1 



Kidney Bean, P/iasea2tM, 6 686.6 926.3 367.3 



Horse Bean, P'ioia 7 676.0 2061.0 266.4 



Potato 3 0.6 0.7 0.6 



Tomato, 5 2.6 2.7 2.4 



Spinage, 4 6.9 9.0 2.4 



Radish, 5 7.1 9.7 6.7 



Lettuce 18 1.1 1.7 0.8 



Parsnip, 3 3.1 3.8 2.3 



Squash 5 173.0 322.0 106.7 



MuskMelon 3 32.9 ■36.6 28.2 



Cucumber, 6 26.4 27.0 21.0 



Timothy, Phleum pratense,. 73 0.41 0.69 0.34 



Bine (iTasB, Poapratensis,.. 28 0.15 0.21 0.10 



Red Clover, 355 1.60 2.08 1.14 



White Clover 63 0.61 0.69 0.47 



Ten-weeks-stocks, Matthi- 



ola annua, 4 1.60 1.60 1.39 



Oak, Quereus pedmnciUata,. 16 2013.4 4213.6 761.6 



It is noteworthy, that in case of Oats, Eye, Wheat, 

 Maize, Beet, Spinage, and Squash, the heaviest seeds 

 weigh ihrice as much as the lightest. With Turnip, 

 Carrot, Kidney-bean, Lettuce, and Blue grass, some 

 seeds are double the weight of others. The horse-bean 

 gives some seeds eight times as heavy as others. The 

 difEerences brought out in the Table in many cases are 

 due to the representation of different varieties ; the 

 larger seeds, to some extent, belonging to larger plants ; 

 but the great range of weight, noted with regard to the 

 seed of the Oat, applies to 15 crops of sound acorns from 

 one and the same tree, gathered in 15 successive years. 



In many varieties of Indian Corn, the kernels at the 

 base of the ear are larger, and those at the tip are 

 smaller, than those of the middle portion. Other varie- 

 ties are characterized by great uniformity in the size of 

 the kernels, Saving been " bred up " to this quality by 

 careful seed-selection. 



It is well-known that the middle part of the ears of 



