Undoubtedly we have in these so-called tails a most hetero- [96] 

 geneous collection of anomalies. Anything appended to the 

 sacral or coccygeal region is described as a tail. Many do 

 actually bear certain resemblances to the tails of lower ani- 

 mals, and have in fact been compared with a great variety of 

 these. On the other hand, some are vesicular or of irregular 

 shape and accompany the condition of spina lifida, while 

 others are to be classed as teratomata or other tumors. A 

 further very significant fact is that a large proportion of the 

 cases have been complicated by the coexistence of ectopia 

 viscerum, hypospadia, atresia ani, or deformities of the limbs, 

 all of which are known to result from amniotic adhesions. 

 This circumstance has led Schaeffer to the conclusion that 

 human caudal appendages are always due to this cause." 



There are, however, a great many cases in which the ana- 

 tomical relations of the tail are such as to indicate that it 

 owes its existence to the persistence of at least part of the 

 vestigeal tail found in the human embryo. In some of these 

 it seems that the coccyx extends down into the tail, though 

 there is no good evidence that there is ever an increase over 

 the normal number of coccygeal vertebrae in these instances. 

 Under this latter head would come the majority of the adher- 

 ent (angewacJisene) tails described by Bartels," and also some 

 cases in which the tail projects free from the trunk as, for [97] 

 instance, cases described by Braun,'" Ornstein," and by Dick- 



wahrscheinliche Ueberbleibsel embryonaler Formen, in der Steissbein- [96] 

 gegend beim ungeborenen, neugeborenen und erwachsenen Menschen. 

 Archiv f. AnthropoL, Bd. xii, 1880. Ecker describes a case reported to 

 him in a letter from Dr. Neumayer, of Cincinnati. 



Miller: Medical and Surgical Reporter, 1881. (Not accessible.) 



8 ArcMv f. AnthropoL Bd. xx, p. 219. 



9 M. Bartels: Ueber Menschenschwanze. Archiv f. AnthropoL, Bd. 

 xiii, 1881. In this paper Bartels classifies persistent tails, dividing them 

 into two main types, adherent and freely suspended (freie) ; of the latter 



a number of subdivisions are made, between which, however, the distinc- [97] 

 tion does not seem to me to be sharp. 



10 M. Braun : Ueber rudimentare Schwanzbildung bei einem erwach- 

 senen Menschen. Archiv. f. AnthropoL, Bd. xiii, 1881. 



11 Ornstein : Schwanzbildung beim Menschen. Archiv f. AnthropoL, 

 Bd. xiii, 1881. 



(3) 



