1888.] NATURAL SCIEN'CES OF PHILADELPHIA. 91 



occasional deformity of the sacral spinal processes and he ar- 

 rives at the conclusion that the sacral pilosity is often connected with 

 attempts at formation of spina bifida. Both Tait and Ecker con- 

 nect the presence of the sacral depression with the formation of an 

 exserted tail. I make the suggestion that the retention of white/black, 

 tan or lemon colored patches at the sacral and lumbar region is an 

 evidence in "tailed quadrupeds of the great activity of nutritive pro- 

 cesses between the superficies and deep-seated parts. It is but a 

 step further, and a legitimate step I think, to connect the sacral pig- 

 ment patches with the subject of sacral tumors which has been so ably 

 elucidated by R. Middeldorpf.' This writer traces the congenital 

 sacral tumors to retention-cysts of the neuro-enteric canal of the em- 

 bryo, as defined by Kowalensky. The canal is the same as the post- 

 anal gut of Balfour. It has been identified in Ascidians, Aviphioxus, 

 and in plagiostome and teleostean fishes. Should the retention of 

 the pigment patch at the superficies of the region where such pro- 

 found changes are seen to occur be proved to be associated with 

 minor degrees of interference at the same region, it follows that in 

 the individuals thus marked, minor changes in the sacral elements, 

 and possibly in the condition of the lumbar swelling of the spinal 

 cord, might be sought for. 



The Back of the Neck. — The region of the back of the neck inclu- 

 ding the withers is well known to be often furnished with a mane of 

 long or short hair. It is of interest to note that in a case of trichosis 

 circumscripta recorded by Virchow'' a distinct pilose growth lay over 

 the region of the third and fourth cervical vertebrae. 



As already remarked p. 88 the breast may be hairy in an animal 

 which in other respects is nearly naked. It remains to mention the 

 gnu in which form a pendant growth of hair from the same region 

 is found associated with an animal having short hair — and a long 

 tail furnished with a terminal brush. 



The dorsi-facial Line. — The region of the head as far as that of 

 the parietal foraminal belongs to the trunk while that in front is 

 distinctive. A white median stripe is commonly found in the region 

 last named in parti-colored dogs. In some varieties a spot of the 

 prevalent color lies directly at the beginning of the trunkal region 

 near the occiput which interrupts the dorsal white line, in the rare 

 instances of its backward prolongation or may be enclosed by it. 

 Mephitis may exhibit a white spot on the dorsum of the face especially 



1 Virchow's Archiv 1885, 101, 37. 



2 Zeitsch f. Ethnologic VII, 279. 



