37 
of the eggs of this pest, such as may guide the farmer in his sowing 
or planting so that the young plant may escape the ravages of the 
young insects. 
INFLUENCE OF TEMPERATURE AND MOISTURE ON GERMINA- 
TION. 
The influence of temperature and moisture on the sprouting of seeds 
has been studied by Sturtevant at Cornell University (Agr. Exp. 
Sta., Bull. No. 7), with results generally confirming those of De Can- 
dolle. Sprouting occurs better with a uniform than with a variable 
temperature, so that the method of Quetelet, which requires us to 
take account of the squares of the temperatures, is no better than that 
which considers the simple temperature. The rapidity of sprouting 
diminishes with the decrease of temperature. The percentage of 
seeds that sprout does not depend upon the uniformity of the tem- 
perature. Sprouting takes place more rapidly in a rather dry soil, 
but a decidedly wet soil is injurious. By soaking the seed before 
planting it, the interval between planting and sprouting is dimin- 
ished, but not between soaking and sprouting; hence the total time 
required and the total percentage of sprouting seeds is not much 
affected by the soaking. 'The exposure to light during germination 
retards some seeds, but does not affect others. Actual planting in the 
field may give 50 per cent less germinations than given by similar 
seeds planted in experimental pots under control. 
INFLUENCE OF LIGHT AND HEAT ON GERMINATION. 
Pauchon (1880) summarizes the results of the studies of many 
authors on the relative influence of light and heat on the germination 
of seeds and the growth of plants. The following section is condensed 
from him: 
Edwards and Colin (1834) state that in their day little was known 
as to the influence of ght and air on the green matter and on the 
respiration of plants; since then, however, it may be considered as 
established that the life of a plant varies in proportion to the adapta- 
tion of the plant to its surroundings. The study of the influence of 
light may be said to have begun with Lavoisier, who thought that the 
heht directly combined with certain parts of the plant producing 
the green leaves and colored flowers, and that without hght there 
could be no life. Similarly Moleschott (1856), at Zurrth, affirms that 
in general everything that breathes or moves draws its life from the 
hght of the sun. 
Boussingault (1876), controverting a statement of Pasteur, main- 
tains that the growth of mushrooms and mold in the dark is not an 
exception but a confirmation of the general rule, and that if the solar 
