hrdliCka] general CONSIDEEATIONS 9 



transverse to the axis of the shaft), by their presence on the ends or 

 edges of the specimen, and by their close similarity in character. 



As to perforations and grooves found in bones, it may be said 

 that many of the most neatly made are due to insects or worms. 

 Numerous examples of this kind due to worms were seen by the 

 writer in the latter part of 1910, during excavations on the 

 Isthmus of Panama. Roots also may produce perforations, especially 

 by enlarging nutrient canals, which are liable to be mistaken for 

 marks of artificial origin. 



It is plain from the preceding remarks that, unless the opening in 

 a bone presents evidence of design or other characteristic such as 

 makes its human origin plainly manifest, it can not be accepted as 

 artificial and is worthless as evidence of man's agency. 



Moreover, even in cases in which perforation in or markings on 

 bones are readily recognized as of human origin, it does not follow 

 that man lived contemporaneously with the animals to which the 

 bones belonged. To be of value as evidence on this point, it must 

 be shown that man worked the bone during the life of tlie particular 

 species and not later. 



As to the bones of fossil animals which show the effects of fire, it 

 needs only to be remarked that in order that such specimens should 

 become available in any case as evidence of man's antiquity, it 

 would be necessary to prove that the fire was due to the agency of 

 man, and that the man was contemporaneous with those animals. 



These various considerations, even though stated very briefly, 

 indicate the complexity of the subject of evidence relating to the skel- 

 etal remains of man or those suggesting man. They show the neces- 

 sity of taking into account every circumstantial detail regarding each 

 distinct discovery of human skeletal parts and the necessity of 

 scientific accuracy in weighing the observed conditions. It might 

 seem that aU the precautions above outlined should necessarily 

 characterize any scientific procedure in this field, but it will be seen 

 in the perusal of the following pages of this paper how readily some 

 of these principles are slighted and even wholly neglected. 



