593 



Harris Hawthorne Wilder 



Fig. 19. Comparison of the main blood-vessels in six cases belonging to the 

 Janus-Omphalopagus series (Mouomphaliens). In all of these the more re- 

 duced aspect (often called "posterior") is above, the more perfect below. 

 When placed in this position, as elsewhere in the paper, the component oh the 

 left is designated as A, the one on the right as B. The upper heart in each 

 of these cases is thus Al -f Br, the lower, Ar + Bi. The right ventricles and 

 the arches proceeding from them, primarily the pulmonary, and the separate 

 pulmonary arteries to single lungs, are dotted, the carotids are striped. Left 

 ventricles and the arches proceeding from them are simply outlined. The 

 small outlined trunks in VI are the subclavians, which in the other cases 

 proceed from the aortse of their respective components. 



The cases in detail are as follows : 



I. Baldwin Synote ; Teras III of the present paper. 

 II. Caloki, 1883. A synotic pig. In this, although there was no face on 

 the imperfect side, the corresponding heart was larger than the other, and 

 from its aortic arch arose the only carotids, supplying the face of the perfect 

 side. No carotids arose from either arch of the heart of the perfect side. 



III. Mayor, 1881. A nearly symmetrical human Janus. Note the connec- 

 tion between the carotid trunk and the pulmonary arch of the perfect side. 

 IV. Debierre and Dutilleux, 1890. A human synote. 

 V. Calori, 1883. A human iniops. 



VI. Wii.r.iAMSOx, ISOij. A human prosopothoracopagus (= gnathopagus 

 of the present paper). 



Of these six diagrams I-IV represent the four possibilities presented by the 

 failure in turn of each of the four arches of the typical rhomboid, although 

 the four sides of the rhomboid are not always constant in the identity of the 

 arches forming them. No. V is like No. II reversed. No. VI is the most 

 aberrant, and comes from that monster in which the components are the 

 most separate, i. e., the most aberrant monster. 



