THE TURTLE. 45 



limb-girdles, and, after the removal of a thin membrane, the 

 viscera. Was either girdle fastened to plastron? Just 

 behind the shoulder-girdle is the heart, and on either side 

 of this the dark liver. In the left lobes of the liver is the 

 stomach. Trace the intestine to the vent. Is there an 

 enlarged terminal portion? Is the intestine supported by 

 a mesentery? Do you find pancreas or spleen? Turn the 

 liver inwards and see the lungs. Are they large? 



In the heart how many chambers? From the front see 

 the vessels. Trace them out, making out carotids, aortic 

 arches, and pulmonary arteries, comparing your work step 

 by step with the frog. What differences do you find 

 between right and left aortic arches when traced to their 

 junction with the dorsal aorta? 



In the body-cavity, behind, are the kidneys. Are they 

 smooth or lobed? Where do their ducts empty? Do you 

 find a urinary bladder arising from the intestine behind? 

 The ovaries are a broad oval, and can usually be recognized 

 by the contained eggs. Where do the oviducts empty? 

 The testes are smaller, long oval, and are outside and behind 

 the kidneys. 



In the skeleton * look for the vertebral column on the 

 inside of the carapace. Is it firmly united to it? Can you 

 find any traces of ribs? If so, in what respects are they 

 peculiar? What parts can you recognize in the shoulder 

 and pelvic girdles? In either limb, beyond the humenis 

 or femur, make out two bones (radius and ulna in the fore 

 limb, tibia and fibula in the hind limb), and beyond this 

 the (how many?) carpal or tarsal bones. How does this 

 explain certain peculiarities in the frog? Draw either 



* Skeletons sufficient for these purposes can readily be made by 

 boiling the specimens and washing away the flesh with the aid of 

 a nail-brush. It is well to boil the head separately. 



