CYCLOPIA IN THE HUMAN EMBRYO. 29 



Most of the epidermis is wanting and in the region of the face are large skin 

 protuberances composed principally of round cells. Such protuberances form the 

 lids of the cyclopean eye, as shown in plate 2, figure 3. The orbital cavity lies 

 upon the cribriform primordia of the maxillary bones and is filled with a single 

 group of pigmented cells, which is surrounded by an infiltration of round cells. 

 Back of this pigmented mass are the primordia of the eye-muscles, but their dis- 

 sociation is so complete that it is impossible to locate the individual muscles, nor 

 can any of the nerves be made out with precision. Aside from the pigmented 

 mass there are no remnants of the layers of the retina, these having undergone 

 complete dissociation. In the upper part of the orbital mass is a curious gland- 

 like structure badly dissociated, which may represent the lacrymal gland. We have, 

 therefore, in this specimen the remnant of a single median eye represented by an 

 irregular but rounded mass of the tapetum situated below the depression of the 

 skin. In turn this depression is partly covered with folds of dissociated tissue 

 which may be recognized as the eyelids of the cyclopean eye. 



CEPHALOTHORACOPAGUS MONOSYMMETROS WITH CYCLOPIA ON ONE SIDE, 

 CARNEGIE COLLECTION No. 1178 a AND b. 



The double female monster, 205 CR and 350 GL long, weighing 1,624 grams 

 was sent to us by Dr. J. I. Butler, Rodgers Hospital, Tucson, Arizona, on May 14, 

 1915. The mother is a Chinese woman, age 24, who has given birth to three 

 children at term and has had two abortions. Apparently the uterus is normal 

 and there is no history of venereal diseases. There is nothing else in the history 

 that bears upon this case. The specimen has been completely dissected by Dr. 

 Theodora Finney, who has given me the notes for the following description of 

 the muscles of the orbit and the nerves of the cyclopean eye. A more detailed 

 account of the anatomy of this interesting specimen will be published by Dr. Finney 

 at some subsequent date. 



The fetus is composed of two nearly complete bodies which lie with their 

 anterior surfaces toward each other, and, as the name implies, are fused from the 

 umbilicus up, forming one thoracic trunk and one head. There are two inde- 

 pendent spinal columns, eight extremities, and two composite fronts, every sym- 

 metrical part of which is formed half of one and half of the other individual. 

 There are also two faces, one of which is well formed, while the other is a synote 

 with a cyclopean eye and snout situated above it. In dealing with the Cyclops, 

 then, it must be noted that its left half is formed from the left side of one indi- 

 vidual, while its right half is from the right side of the other individual. 



Internally the thoracic and abdominal viscera are double, with the exception 

 of the esophagus, the stomach, and the upper part of the intestine, which are 

 united with a single canal. There are two central nervous systems, separate and 

 complete to above the level of the two hypophysi, where fusion occurs. As much 

 tissue was lost from the region of the thalami in removing the brain, the mode of 

 union of the base of the brain could not be determined. An optic chiasm, how- 

 ever, belonging to the well-formed face, remains in vi(u immediately behind the 



