4:8 ELEMENTS OF COMPARATIVE ZOOLOGY. 



COMPARISONS. 



Prepare a sheet of paper with two columns as before, one 

 for fishes and the other for the frog and tadpole, and give 

 answers to the following questions: 



(1) Is the skin naked or scaly ? 



(2) What kind of appendages occur ? 



(3) Is the pelvic girdle united to the back-bone " 



(4) Is there an Eustachian tube ? 



(5) What differences are there in the heart ? 



(6) What are the organs of respiration ? 



(7) Do the nostrils communicate with the mouth ? 



(8) Differences between transverse processes and ribs ? 



(9) Is a sternum present ? 



