248 



FOUNDATIONS OF BOTANY 



under a power of 200 or more diameters. Select the terminal cell 

 of the leaf if Chara is used. The protoplasm is nearly colorless but 

 usually contains bodies which can be seen moving in the current of 

 protoplasm. The protoplasm will show 

 normal activity at the temperature of a 

 comfortable living room. By focusing, see 

 if the current of protoplasm can be detected 

 moving in more than one direction. 



Note the form and arrangement of the 

 chlorophyll and any places lacking chloro- 

 phyll, and see if you can tell whether the 

 arrangement has any relation to the current 

 of protoplasm. With a low power trace the 

 course in several cells. How many cells con- 

 stitute each internode of Nitella 1 If Chara 

 is used, internodes will be found to be 

 covered with a layer of many corticating 

 cells. Under a high power compare the 

 general structure of node and internode and 

 see if the attachment of leaves and branches 

 can be clearly determined. Compare the tip 

 of a leaf with the tip of a stem or branch 

 if the material permits. Are the fruiting 

 organs produced on the sterns or the leaves ? 

 288. Antheridia. The antheridia are 

 globular bodies, bearing male fertilizing 

 cells and becoming red at maturity (Fig. 

 182). Eight cells compose the outer wall. 

 They have radial lines indicating folds and 

 join one another by irregular sutures. Note 

 a round spot in the middle of each cell 

 which marks the point of attachment within 

 of the stalk on which antherozoid-producing cells are borne. 



289. Oogonia. The egg-shaped fruits, known as oogonia (Fig. 

 182), are borne near the antheridia in monoecious species. Count 

 the number of pointed cells which constitute the " crown " of the 

 fruit. Does each tip consist of one or two short cells ? Examine 



FIG. 181. End of a Main 

 Shoot of Chara. (About 

 natural size.) 



