908 



TERATOLOGY. 



preserved in the splendid Museum of the 

 London College of Surgeons. 



c. In the anterior mediastinum* As in a case 

 recorded by Gordon, in a female of twenty- 

 one years. 



d. In the scrotum and the testes. Such 

 cases have been noticed by Rosenberger, 

 Hartmann, D S. J. Wendt, Velpeau. Some- 

 times the rudiments of a second foetus are 

 found in the interior of the testis, sometimes 

 at its exterior surface. 



e. In the stomach. 



f. In the intestinal canal. High more has 

 piven such a case in a youth of fifteen or six- 

 teen years, in the gut of whom an acephalus 

 was found. 



g. In the orbit. According to Barnes. 

 h. At the tentorium of the dura mater. 



1. At the palate. It is then in the form 

 of a fungous excrescence, consisting of the 

 rudiments of a second foetus (Otto, Sancli- 

 fort, Ehrman, Stadenski). 



2. The more or less developed rudiments of 

 a ftelits adhere, in the form of a tumour t 

 to the external surface of a second body, 

 and are covered by the external intcgu- I 

 mcnts. 



a. To the cheek. G. Vrolik observed in a 

 new-born male child, a sac of large circum- 

 ference, covered by the external skin, and ad- 

 hering to the region of the left cheek, but 

 without communication with the mouth. In 

 this sac there were tuberculous cartilages, os- 

 seous nuclei, and organised parts of indefinite 

 form and composition. 



b. To the neck. According to Joube. 



c. To the epigastric and umbilical region. 

 As recorded by E. B. Gaither. 



d. To the sacral and perineal region. This 

 is the most frequent mode of adhesion, as is 

 proved by a great many observations, among 

 which those of Himly and of Fleischmann 

 deserve special mention. This adhesion takes 

 place in different manners : 1. by external 

 cellular tissue ; 2. by internal union with the 

 abdominal and pelvic cavity (Himly, Schau- 

 mann, and Stanley) ; 3. by communication 

 with the spinal canal. There is sometimes 

 no vascular communication between the foetus 

 and its appendix (W. Vrolik) ; and in other 

 cases there are large branches going from the 

 arteria sacra media of the foetus to the sac. In 

 general, the sac has its own integuments, over 

 which passes the skin of the foetus. The 

 genital parts and the anus are always quite 

 separate from the sac, which merely lies in 

 apposition with them. In the majority of 

 the known cases, the rudiments of a foetus 

 contained in the sac are but confused and 

 ill-determined organic substances, intermin- 

 gled with a few osseous and cartilaginous 

 nuclei. In one case it was possible to recog- 

 nise the cranium with the face and the naked 

 encephalous masses (Wedemeyer) ; Mayer 

 and Blizard found an intestinal loop ; Himly 

 saw distinct super-maxillary bones, and ru- 

 diments of temporal, frontal, and sphenoid 

 bones, &c. 



If we take a survey of all the cases which 

 are designated asfcetus in fuetu, it is clear that 

 some may be compared with parasitical dis- 

 eases formed in the interior of the body of 

 the foetus. 1 presume that this is the case, 

 when the mass which is found consists only 

 of hair, fat, teeth, and some osseous nuclei, 

 contained in a cystic tumour. In other cases 

 the rudiments of a foetus are included with a 

 more or less perfect indication of an ovum in 

 the body of a second foetus, or adhere exter- 

 nally to it. The large number of theories on 

 the origin of this monstrosity have been criti- 

 cised by Himly. It is certain that none of 

 them can be maintained. It is most pro- 

 bable that the foetus infcetu is an incomplete 

 effort to form a double monster. In this 

 sense, some cases o(' ftetus in fcetu make a 

 transition towards that form of double mon- 

 sters which is named lieteradelph. 



II. Double Monsters, in which one of the Fee- 

 fuses is more or less perfect and the other 

 merely an Appendix to it (llcteradclphi) . 

 Under this name of heteradelphs, which we 

 owe to Geoffroy St. Hilaire, we understand 

 that species of double monsters of which 

 one foetus is large and perfect, and another, 

 or part of another, adheres to it like a para- 

 site. They should be considered as twins, of 

 which one has been developed at the expense 

 of the other, which other sometimes becomes 

 partially included in its body. According to 

 the more or less perfect state of the appen- 

 dix, they are reduced to different species. 



First Species. The appendix consisting 

 of a head only. This may be connected : 



1. With the epigastric region (Winslow, 

 Hesse), 



2. With the cranium (E. Home), 



3. With the back (Chabelard), 



4. With the palate (Hofmann), or 



5. With the under-jaw of the perfect foetus 

 (Geoffroy St. Hilaire, G. Sandifort). 



Second Species. The appendix consists 

 of more or less developed extremities only. 

 Supernumerary extremities, more or less deve- 

 loped, are connected with some part of the 

 body of a perfect foetus, as : 



1. Pelvis and two inferior extremities con- 

 nected with the epigastric region of the per- 

 fect foetus (Serres, E. Sandifort, Trombelli, 

 Mayer, Winslow, Reschel, Buxtorff, Cantwell, 

 Lycosthenes). 



The appendix is sometimes more, sometimes 

 less perfect ; sometimes connected with the 

 sternum, sometimes with the epigastric region 

 or in communication with them by a cylin- 

 drical cutaneous prolongation. In the appen- 

 dix are regularly formed organs of generation, 

 kidneys, an intestinal loop in communication 

 with the intestinal canal of the supporting 

 foetus, and vessels which anastomose with 

 those of the latter. The adhering parasite is 

 therefore one with its supporter. 



2. Pelvis and the two inferior extremities 

 connected with the lateral wall of the abdo- 

 men of the perfect foetus (W. Vrolik). 



3. Pelvis and two inferior extremities con- 



