58 ABNORMAL CONDITIONS OF THE AXIS. 



231. The viscera of the same. The lungs are very small, and 



both are of nearly equal size ; each has but two lobes. 

 The intestine terminates in an enormously dilated colon. 



232. The external integument of the united limbs of the same 



foetus. 



233. A similar foetus, with the skeleton of the stump and lower 



portion of the body exposed. This specimen shows the 

 peculiar flexure of the spine well, the fusion of the bones 

 of the limb, and their excessive rotation. There are two 

 patellse. Presented by Dr. W. G. Sheppard, 1867. 



b. Monojpodia. 



234. A similar foetus, with the muscles of the lower half removed 



to show the skeleton. The pubes and ischia are fused. 

 There is but one limb, as far as the skeleton is concerned. 

 The tibia terminates in a point. 



Presented by J. F. Steedman, 1864. 



235. The skin of the conical stump-like limb of the same. A 



small nipple-]ike prominence only represents the right 

 limb. Presented by J. F. Steedman, 1864. 



236. The thoracic viscera of the same, exhibiting situs mutatus, 



or transposition. Presented by J. F. Steedman, 1864. 



237. A small Human foetus with monopodia, about the sixth 



month of gestation. A section has been made through 

 the head and trunk as well as through the single stump, 

 which represents the lower limb. The spine is contorted, 

 the pelvis cannot be recognized. The limb terminates in 

 a rounded stump, like that of an amputated limb. The 

 patella is turned backward, and a small square piece of 

 cartilage only represents the distal extremity of the limb. 



Subclass III. Arrest of the whole axis. 



Syn. Amorphus, Gurlt. 

 Omphalosites, Geoff. 



Monstres Paracephaliens et Acephaliens, id. 

 Anideus, id. 

 Acardia, Forst. 



Deficiency of the heart appears to be the most constant cha- 

 racter of general arrest of development. The head is frequently 

 absent ; when present it is always rudimentary and malformed. 



