A YEAE IN SCIENCE 97 



ment. Make similar observations on the corn. In what 

 manner does it send its shoot through the soil ? Sketch. 

 Examine a number of other seedlings and place them 

 under the proper one of the above classes. 



D. The growth above the ground is called the 

 shoot (stem and leaves), while that below is the root. 

 The points on the stem from which the leaves grow 

 are called nodes. The portion of the stem between 

 two nodes is the internode. Sketch a pea seedling to 

 show nodes and internodes. 



Examine well grown seedlings of peas and beans. In 

 each instance where are the cotyledons, above or 

 below the surface of the soil? What is their present 

 condition? What does this indicate as to the function 

 of the cotyledons? What change has the plumule 

 undergone? Is there a new plumule? Sketch to show 

 the above points. 



CHAPTER XV 



FRIENDS AND ENEMIES OF LIVING ORGANISMS 



Exercise 66. Bacterial Cultures. 

 Object: To show the prevalence of bacteria and 

 something of their nature. 



Apparatus 



Petri dishes Steam sterilizer 



Culture media (gelatine, agar, Inoculating tubes 

 and potato)* Dissecting needles 



*Culture media ready for use may be obtained from dealers 

 in laboratory supplies. 



