PRESERVATION OF THE SPECIES 171 



Monoecious, the different kinds of reproductive organs 

 found in the same individual. 



Directions. 



Note. — Refer to your notes, if the animals mentioned in these exer- 

 cises have been already studied. This exercise may be largely review. 



Study the methods of reproduction in the specimens or 

 diagrams before you. Determine first, in what respects 

 the methods of reproduction are similar in all ; second, in 

 what respects there is a variation. 



Questions. 



1. What has an amoeba gained by dividing.? What 

 powers has each new cell that the original amoeba had 

 lost } What would have been the fate of the amoeba if it 

 had not divided into new cells .' 



2. What various forms of cell division did you find } 



3. What is the simplest method of reproduction .-• 



2. The Complex or Sexual Method of Reproduction 



Materials. 



Slides or diagrams showing hydra and sponge reproduc- 

 ing sexually. Conjugating paramecia, fertilized and un- 

 fertilized starfish eggs. 



Directions. 



Identify the reproductive organs or gonads of the hy- 

 dra. These are slight swellings on the surface. The one 

 nearer to the mouth end is the spermary and that near the 

 attached end is the ovary. 



Questions. 



I. How is an egg cell produced in hydra.' In general 

 how do the reproductive cells of sponges and hydra 

 originate .' 



