376 • Harris Hawthorne ^^'ilcle^ 



is apparently a single organ, Ijut that of the imperfect side is narrower 

 than normal, yet not incomplete, while that of the perfect side is appar- 

 ently a normal one. From each larynx a trachea leads down into a 

 pair of kings, the pair npon the perfect side being in reality Ar-f-Bl 

 and that of the imperfect side, Br-|-Al, reading in each case from left 

 to right, as is natural. 



In the chest region the imperfect side is being gradually rolled out 

 and is thus becoming more nearly the equal of the other. This may be 

 readily shown by ascertaining the degree of inrolling at two levels, for 

 example, (1) at the acromia and (2) at the nipples, and comparing 

 th^ two. The distance l^etween the acromion processes of the perfect 

 side is 7.1 mm., and between those of the imperfect 48 mm. In the case 

 of the nipples, which are situated at a lower level, the distance between 

 them on the two sides is 36.5 mm. and 29.5 mm., respectively. If in 

 each case we consider the measurement for the perfect side as 100, that 

 for the imperfect side at the level of the acromia is but 67.6 per cent of 

 it, while at the nipple level the measurement of the imperfect side is 

 80.8 per cent of that of the perfect one. The sternum of the imperfect 

 side shows this change throughout its length, as it is somewhat narrowed 

 anteriorly and a little rolled in, as if by the close approximation of the 

 shoulders, but posteriorly it is practically like that of the other side. 



The alimentary canal well illustrates the principle of the secondary 

 modification of an organ through embryonic functional activity, since 

 for some weeks previous to birth the intestine has been made the recep- 

 tacle for the meconium and has had more or less to do with the function 

 of nutrition. The common oesophagus leads into a common stomach, 

 though evidently one formed of two components, since it presents two 

 cardiac enlargements, one on either side of the cesophagus. Tl o outline 

 of the stomach is thus heart-shaped, but is not quite symmetrical, since 

 the cardiac lobe of component A is a little larger than that of B. The 

 stomach leads through a single pylorus into a common intestine, whicli 

 continues single throughout about three-quarters of its length (80.9 cm.) 

 and then divides into two, which extend to the two colons located in the 

 separate components, the connecting piece of A being 29.3 cm., and 

 that of B 25 cm. in length. Beyond these extend the cseca, appen- 

 dices, and colons of each individual, that of A being 21.6 cm. in length, 

 and that of B 27 cm. As the intestinal canal is a common one from the 

 united phar^^nges to the bifurcation at the lower fourth of the small 

 intestine, the decision as to physiological function comes at this latter 



