DUPLICITY. 33 



at the inner side of the nostril is a deep fissure, probably the re- 

 mains of the nasal cavity ; this fissure is marked by a purple glass 

 rod. The left upper alveolus has been exposed by the removal 

 of the giim, and is very distinct. 



One of the largest of the fatty lobes, which make up the bulk 

 of the tumour, has been cut through to show its structure. It 

 consists of firm vascular fat with an atheromatous centre. A 

 small cyst appears at its upper part. On the right side there is a 

 piece of adherent placenta, and just below it is a loose, pendent, 

 lobulated mass about an inch and a half in diameter. As one of 

 its lobes felt very hard it was opened, and was found to contain a 

 compact mass of bones, fifty-nine in number (see No. 132). The 

 skin of the tumour is soft, vascular, and covered with lanugo. The 

 lobe which contained the bones presents three indistinctly separate 

 hard white papilla?, something like aborted digits. 



The most remarkable point in this specimen is that lips and 

 alveoli only are well developed upon the tumour, as if its position 

 had determined the nature of the part developed. There can be 

 no reasonable doubt that the tumour consists of the remains of a 

 second embryo. 



132. Fifty-nine ossicles from the tumour in the last preparation. 



They are most complex in form, and were closely packed 

 together. There is but one which resembles any normal 

 bone, the first of the series ; it appears like the lamina of 

 one of the cervical vertebrae. 



133. The superior maxillary bone and a portion of the malar 



bone from the same, taken from the right side of the 

 tumour. These belonged to the foetus and not to the pa- 

 rasite growth. It is normal, although it supported a por- 

 tion of the tumour. 



B. By Inclusion. 



Syn. Cryptodidymus, Ourlt. 

 Fo3tus in Fcetu. 



Sometimes instead of a second embryo becoming impacted in 

 the visceral arches of another, it becomes enclosed within its ab- 

 dominal cavity. The included embryo in. these cases is contained 

 in a cyst, and connected with it by an imperfect funis. Under 

 these circumstances it may live and grow for many years. It 

 is always excessively defective and much deformed. Both the 

 including subject and fostus arc usually male. 



