ANATOMY OF THE DRILL. 



439 



from those in the Baboons. The left lateral lobe is smaller ; the 

 left central lobe is not so wide, and its free margin is notched. 

 The i-ight central lobe is intimately united to the left central 

 lobe, and its free edge is more rounded. The right lateral lobe, 

 caudate and Spigelian lobes are lai'ger relatively to the others 

 than in the Baboons. 



Text-figure 15. 



The hver (A.) and trigone of the urinary bladder (B,)- Ct.B : gall-bladder; V : 

 umbilical notch ; left lateral (L.L.), left central (L.C.), right lateral (R.L.), 

 right central (R.C.), caudate (C), and Spigelian (S.) lobes. 



The lateral fissures are deep, the fissui'e of the ductus venosu? 

 is marked, and the umbilical fissure is bridged over. The vena 

 caval fissure is not bridged over, and the vein is superficial. 



The Ductless Glands. 



The spleen (text-fig. 17 B) is flat and triangular, with rounded 

 angles. The hilum is not linear, as in many Mammalia, but 

 occupies an oval area into which tortuous vessels and sympathetic 

 nerves enter. 



The suprarenal cajisules are small, thin, flat, and helmet- 

 shaped, and lie in the usual positions. Each receives two small 

 arteries from the abdominal aorta and one' from the renal artery. 

 The sympathetic plexuses, especially those to the left gland, are 

 very rich and closely related to other abdominal plexuses. 



The oval lateral thyroid lobes are unconnected, and lie against 



