EEPEODUCTIVE ORGANS OF PLANTS. 



341 



Absolute Weight of Commercial 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 13.0 



Wheat, 96 37.6 45.8 15.2 



Maize, 22 282.7 382.9 114.5 



Beet, 39 22.0 42.4 14.2 



Turnip, Brassica rapifera,.. 23 2.2 3.0 1.4 



Carrot, 35 1.2 1.7 0.8 



Pea, 43 185.8 564.6 46.1 



Kidney Bean, Phaseolus 5 585.6 926.3 367.3 



Horse Bean, Vicia 7 676.0 2061.0 256.4 



Potato, 3 0.6 0.7 0.5 



Tomato, 5 2.5 2.7 2.4 



Spinage, 4 6.9 9.0 2.4 



Radish, 5 7.1 9.7 5.7 



Lettuce, 18 1.1 1.7 0.8 



Parsnip, 3 3.1 3.8 2.3 



Squash, 5 173.0 322.0 106.7 



Musk Melon, 3 32.9 35.5 28.2 



Cucumber, 6 25.4 27.0 21.0 



Timothy, Phleum pratense,, 73 0.41 0.59 0.34 



Blue Grass, Poa pratensis, . . 28 0.15 0.21 0.10 



Red Clover, 355 1.60 2.08 1.14 



White Clover, 53 0.61 0.69 0.47 



Ten-weeks-stocks, Mattlii- 



ola annua, 4 1.50 1.60 1.39 



Oak, Quercus pedunculata,. 15 2013.4 4213.5 761.6 



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

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

 weigh thrice 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 

 differences 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 Oak, 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, having been " bred up " to this quality by 

 careful seed-selection. 



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



