36 



MORPHOLOGY OF THE 



the embryo was occupied by the colon as it entered the 

 abdomen from the cavity of the umbihcal cord. The one on 

 the right by the jejunum as it was about to leave the body 

 cavity. This portion of the intestine also grooves the right 

 lateral lobe. From this point of view, the right lateral 

 appears to be actually larger than the right central lobe, 

 although in reality this is not the case, but it is very much 

 larger in proportion, as compared with the adult. 



The left lateral lobe is deeply concave for the fundus of 

 the stomach, and the oesophageal groove is seen close to the 

 median line of the organ. 



The pylorus rests upon the Spigelian lobe, and gently 

 grooves it to the right of the cross, which marks the apex 

 of this lobe. The apex touches the lesser curvature of the 

 stomach, or possibly reaches a hair's breadth caudad from it. 

 The lesser omentum lies ventrad from the lobe. It will be 

 noticed that at this stage the relation of the Spigelian lobe 

 to the stomach closely resembles that of the adult cat. 



The duodenum begins close to the median line, and its 

 second portion is situated to the left of the jejunum, in front 

 of, and to the right of, the pylorus. It groves the right cen- 

 tral, the right lateral, and caudate lobes, and its loop, or third 

 portion, rests upon the latter lobe. Its position is quite dif- 

 ferent from that of the adult, for it will be remembered 

 that in the adult from one quarter to one third of the upper 

 part of the second portion of the duodenum rested upon the 

 caudate lobe, whereas in this embryo its third portion is in 

 relation to it. 



Fig. 22 represents the caudal surface of the liver of an 

 embryo 61 mm. in length. The different lobes can be easily 

 differentiated, and it will be observed that the caudate and 

 Spigelian lobes are at this stage of development particularly 

 prominent. 



The fundus of the stomach is contained in a deep fossa 

 formed by the left lateral lobe, while its pyloric extremity 

 rests upon and grooves the Spigelian lobe. The duodenal 

 groove is well marked as it curves over the right central and 



