I STUDY OF COMMON PLANTS. 



h. Near the hilum a minute orifice, micropyle, easily 

 seen under a lens (plainer in the pea). 



c. The ohalaza, the part where the seed coats blend 

 with each other and nutriment enters the grow- 

 ing seed. In this case the chalaza is located 

 externally by a small protuberance near the 

 hilum, on the opposite side from the micropyle. 



II. With a sharp penknife or needle remove the integ- 

 ument, testa, from a bean that has been soaked in. water 

 for a day. Near the hilum a small pointed body, the 

 radicle, will be found. Locate it accurately. Does it 

 have any relation to the micropyle ? 



III. Separate the two halves, cotyledons. Examine 

 under a good lens. Notice 



1. The form and position of the radicle. 



2. The delicate structure, plumule, connected with it. 

 Draw the parts, taking care to represent accurately 



the leaves of the plumule and their venation. 



IV. Examine beans that have lain a few days on moist 

 blotting paper under a bell-jar. What changes have taken 

 place ? 



What part of the seed has developed into the primary 

 root ? What changes has the plumule undergone ? 



V. With the common bean compare a number of other 

 varieties, " butter bean," " scarlet runner," etc., noting 

 carefully all points of likeness and difference. 



VI. Study next the common pea, comparing its struc- 

 ture with that of the bean. 



VII. Write a detailed account of your observations of 

 the bean and pea. Introduce drawings or outline sketches 



