ANNULATA. 205 



6. Investigate parasitism among the annulata. 



7. In what different ways is respiration effected in the 

 group? What is the relation of the method to the life 

 habits of the animal in each case? 



8. Enumerate the various ways in which it seems to 

 you the earthworm is especially adapted to its particular 

 method of life. 



9. Make a report on reproduction by division (fission) 

 in this group. What are the chief points of difference in 

 the different species? 



10. How is cross-fertilization secured in the earthworm? 



1 1 . Compare the earthworm and hydra as to the rela- 

 tion between the digestive cavity and the body wall. 

 How do the tissues get the digested food in each case? 



12. Select and undertake some special spring studies 

 as to the habits and behavior of some members of this 

 group. 



13. Of what value are worms as food to the higher 

 animals ? 



