GERMINATION AND GROWTH 33 



perceptible in germinating seeds and young leaves, in buds 

 and flowers, where active work is going on. Hence, in this 

 condition they consume proportionately larger quantities 

 of oxygen and liberate correspondingly larger quantities of 

 carbon dioxide, with a proportionate increase of heat. In 

 some of the arums, — calla lily, Jack-in-the-pulpit, colo- 

 casia, etc., — and in large heads of compositse, like the sun- 

 flower, where a great number of small flowers are brought 

 together within the same protecting envelope, the rise of 

 temperature is sometimes so marked that it may be per- 

 ceived by placing a flower cluster against the cheek. 



Practical Questions 



1. What is charcoal ? (28.) 



2. Is any of this substance contained in the seed? in the flour and 

 meal made from seed? (28; Exp. 25.) 



3. What combination takes place when the cook lets the stove get too 

 hot and burns the biscuits? (27, 28.) 



4. Of what does the burned part consist? (28.) What was it before 

 it was burned? (27,28). 



5. Which burns the more readily, an oily seed or a starchy one? 

 Which leaves the more solid matter behind ? (Suggestion : test by put- 

 ting a bean, or a large grain of corn, and an equal quantity of the kernel 

 of a Brazil nut on the end of apiece of wire and thrusting into a flame.) 



6. Is there any rational ground for the statement that the wooden 

 buildings formerly used on Southern plantations as cotton ginneries were 

 sometimes destroyed through spontaneous combustion due to the heat 

 generated by piles of decaying cotton seed ? (Exp. 25, Note.) 



n. CONDITIONS OF GERMINATION 



Material. — Several ounces each of various kinds of seed. For the 

 softer kinds, pea, bean, corn, oats, wheat are recommended ; for those 

 with harder coverings, squash, castor bean, apple, pear, or, where ob- 

 tainable, cotton ; for still harder kinds, persimmon and date seeds, or the 

 stones of plum and cherry. 



Appliances. — 1 dozen common earthenware plates for germinators ; 

 1 dozen two-ounce wide-mouthed bottles; 2 common glass tumblers; 

 clean sand, sawdust, or cotton batting, for bedding ; a double boiler ; a 

 gas burner, or a lamp stove. 



