ENCEPHALOCELES AND OTHER ABNORMALITIES. 93 



three and is cone-shaped, whereas the other two are smaller and hemispherical. 

 All are of soft consistency. The large conelike swelling measures 6 cm. from the 

 superior margin to its tip and 2.5 cm. from tip to inferior margin, its base being 

 circular and measuring 4.3 cm. in diameter. This cone lies pendant over the back; 

 the proximal half of its superior surface is covered with scalp and fine brown hair 

 2.5 cm. long. A strip of coarser hair of the same length follows the median margin 

 of the swelling to its lowest point. The covering of the distal half of the superior 

 surface and the entire inferior surface resembles smooth, fine-grained leather. No 

 hairs are present, but it is dotted with minute pores which on microscopical exami- 

 nation are seen to be the mouths of sweat-ducts. The wall of the sac is 3 mm. 

 thick, a section through which shows an extremely thin layer of epidermis lying 

 immediately over a vascular connective tissue, containing the sweat-glands men- 

 tioned above, but no hair follicles. There are two oval naBvi near the tip of the 

 sac, which in the gross resemble scars. These lie in the same long axis directed 

 laterally through the tip of the sac. The smaller of the two is 5 mm. to the left 

 of the tip and measures 7 by 3 mm. The larger lies 10 mm. to the right of the tip 

 and measures 25 by 17 mm. The color of these areas is lighter than the surround- 

 ing tissue and the surfaces are stiff, smooth, and slightly raised. In their neigh- 

 borhood the thickness of the sac wall is increased to 9 mm. Histologically the 

 epithelium is lacking here and a very vascular connective tissue forms the raised 

 surface. The lining of the upper part of the sac is smooth fibrous tissue contin- 

 uous with the dura of the main cerebro-spinal cavity. Near the tip, however, it 

 is made up of shaggy strands of blood-vessels whose complicated, interweaving 

 pattern is like the early capillary plexus of the dura, as described by Streeter (1915). 

 This suggests that the irregular vascularization in this region may be due to arrested 

 development of the vascular system. There is marked engorgement of these vessels 

 and congestion in all the tissues. Part of this extreme engorgement was probably 

 caused by birth trauma. 



The left encephalocele measures 5 by 4 cm. and protrudes 1 cm. from the 

 surface. Its upper half is covered with fine hairs and the lower half with normal- 

 appearing skin. The wall is 1 to 2 cm. thick, composed chiefly of a layer of sub- 

 cutaneous fat. On its left lower border there is a rounded bleb of porous, wrinkled 

 skin 1 cm. in diameter, over which arc scattered a few hairs 2 cm. long, and which 

 contains around its depressed circumference a much thicker growth of similar hairs. 

 A section through the wrinkled skin shows that it lies over a funnel-shaped canal, 

 the wider mouth of which extends down through 1.5 cm. of subcutaneous fat to 

 the subdural space, where the canal becomes narrow. This canal is filled with fluid 

 and contains a few blood-vessels supported by loose connective-tissue septa. Its 

 walls are formed of rather dense connective tissue. 



The right encephalocele is 4 cm. in diameter at its base, and the surface, which 

 is covered with hairy scalp, is but slightly raised above the adjoining structures. Its 

 wall, consisting of epidermis, connective tissue, and fat, is but 3 mm. thick. 



A summing up of the integument findings shows that both normal skin and 

 scalp are found over the areas adjoining the encephaloceles and over parts of the 



