PLATYPUS AND ECHIDNA. 



spleen are related to the lesser sac (great omentum), 

 while the left process is outside the lesser sac and connec- 

 ted to the mesocolon of the descending part of the left or 

 distal colon by the left lateral or lieno-mesocolic fold. 

 The great omentum comes down as far as the upper 

 border of the colon, but does not include it; and the pan- 

 creas — after more or less tilling the duodenal loop as 

 stated — is prolonged along the upper border of the colon 

 as a process forming the lower dorsal boundary of the 

 lesser sac, extending in an average specimen for about 2-3 

 cm. (It is to be noted that the main mass is above the 

 colic relation to mesoduodeiiuni, only a small amount 

 being found dorsal to the commencement of the mesen- 

 tery, while the reverse is the case in Platypus.) 



In contradistinction to the Platypus the pancreas 

 does not extend to the left beyond the lesser sac, i.e., does 

 not come into relationship with the posterior process of 

 the spleen and the lieno-mesocolic fold. There is usually 

 a well defined groove in the pancreas for the reception of 

 the colon. 



(5) In a male adult specimen the pancreas on the 

 right was closely related to the lobus caudatus of the liver 

 (thus lessening duodenal mobility), so that the whole 

 organ could be regarded as fixed. In this mammal the 

 distal colon was fixed, and not only the body and right 

 process, but also the stem of left process of spleen, were in 

 the lesser sac, only the nummular process being outside 

 and related to colon. The lesser sac dipped down sinistral 

 to the distal colon, and the pancreas also extended down 

 on the left of the colon. The lesser omentum and the 

 foramen Winslowii were poorly defined. 



(6) In the Platypus the separation between meso- 

 duodenum and gastro-hep. omentum is ill defined, 

 and a gap is noted dorsal to the bile duct, i.e., fora- 

 men of Winslow. A band is noted (of which a 



or; 



