I.] DISSECTION OF A BABBIT AND OF A DOG. 23 



jS. There is in the neck no separate nerve corre- 

 sponding to the depressor in the rabbit. 



y. The sympathetic and the vagus run in the neck 

 in a thick sheath common to both. At the lower 

 end of the neck, the sympathetic joins the infe- 

 rior cervical ganglion. From the ganglion run 

 several pale nerves to the heart and lungs, and 

 receives two white ones — the annulus of Vieus- 

 sens — from the first thoracic ganglion. The 

 latter receives rami from the lower cervical and 

 first two dorsal nerves, of these the 2nd dorsal 

 only (the 10th spinal nerve) gives an obvious 

 white as well as a grey ramus to it. 



30. Clear away any muscles that may remain around 

 the lower part of the larynx; on either side 

 of it is attached a thin, dark red lobe of the 

 thyroid gland, the lobes run a short way down 

 the trachea, and there join over the ventral 

 surface of the trachea by a very thin connecting 

 piece. 



D. 1. Cut through the skin in the front of the thigh 

 and turn it back on either side; in the upper 

 median part blood-vessels will be dimly seen 

 through the thin sartorius muscle ; cut through 

 this muscle and note the femoral (crural) 

 artery and vein, and the crural nerve run- 

 ning side by side ; trace the artery upwards, 

 it unites with other arteries to form the common 

 iliac, which with the common iliac of the other 

 side forms the abdominal aorta ; trace similarly 

 the femoral vein to the common iliac vein and 



