GERMINATION. 313 
Lowest Highest Temperature of most 
Temperature. Temperature. rapid Germination. 
Wheat, 41° F. 104° F. 84° F. 
Barley, 41. 104. 84, 
Pea, 44.5 102. 84, 
Maize, 48. 115. 93. 
Scarlet-bean, 49. 111. 79. 
Squash, 54. 115. 98. 
For all agricultural plants cultivated in New England, 
a range of temperature of from 55° to 90° is adapted for 
healthy and speedy germination. 
It will be noticed in the above Table that the seeds of 
plants introduced into northern latitudes from tropical re- 
gions, as the squash, bean, and maize, require and endure 
higher temperatures than those native to temperate lati- 
tudes, like wheat and barley. The extremes given 
above are by no means so wide as would be found were 
we to experiment with other plants. It is probable that 
some seeds will germinate nearly at 32°, or the freezing 
point of water, while the cocoa-nut is said to yield seed- 
lings with greatest certainty when the heat of the coil is 
120°. 
Sachs has observed that the temperature at which 
germination takes place materially influences the relative 
development of the parts, and thus the form of the seed- 
ling. According to this industrious experimenter, very 
low temperatures retard the production of new rootlets, 
buds, and leaves. The rootlets which are rudimentary in 
the embryo become, however, very long. On the other 
hand, very high temperatures cause the rapid formation 
of new roots and leaves, even before those existing in the 
germ are fully unfolded. The medium and most favora- 
ble temperatures bring the parts of the embryo first into 
development, at the same time the rudiments of new or- 
gans are formed which are afterward to unfold. 
&, Moisture.—A certain amount of moisture is indis- 
pensable to all growth. In germination it is needful that 
; 14 
