Tasvtan idii Crania. 123 



In selectinf? this plane, Schwalbe was coniijelled to \n;\\s(i use of tlie 

 glabella as one of the fixed points, owintr to the fact thnt in ealvaria 

 of PitJiecanthropus erecius, the face is niissinji^, a remark which also 

 applies to many of the other calvaria examined by S hwalbe, and 

 which left him no choice in the matter. In deciding on this plan he 

 says: — "so erweist sich als eiiifachste und natiirlichste die voiii 

 vorderen Glabellarende bis zu deiii am vveitesteii iiach hinten voi-ra- 

 genden Medianpnnkte des queren Hinterhauptwnlstes, welchen Dubois 

 als " scheinbares Inion " bezeichnet hat. Ich schlectliia als Fnioii 

 bezeichnen werde." 



In their researches on the Tasmanian crania, Berry and Robert- 

 son (5) also adopted, in the first place, Schwalbe's methods of " form 

 analysis,"' based on the glabella inion plane, as they were anxious to 

 institute comparisons of evolution between the Tasmanian and primi- 

 tive man. Klaatsch (6), in his memoir on the Australian crania, also 

 adopted the glabella inion plane. He says: — '"To secure a common 

 standard I take the glabellar point and glabellar inion plane," and 

 again, " for pur230ses of the more precise comparative investigations 

 with the fossil fragments, the glabella inion plane is clearly prefer- 

 able." In his later works, however, he departs from the base line. 

 Turner's (7) base line, that is, the nasio-tentorial plane, when avail- 

 able, appears to be one of the most satisfactory and rational planes 

 for craniologicai purposes. In selecting this plane in opposition to the 

 glabella inion plane, he states that the variation of the glabella, in 

 association with the frontal sinus, " unfits it to be used for taking 

 the point in front from which to estimate the length of the cerebral 

 part of the cranial cavity." 



Berry and Robertson (5) agree with Turner that the glaljella inion 

 plane is not the best (when others are available), " from which to esti- 

 mate the cerebral part of the cranial cavity," but consider that "' the 

 nasio-inion plane coincides more closely with the cerebral part of the 

 cranial cavity than either the glabella inion or nasio-tentorial planes."' 



The influence of the frontal sinus on the glabellar region has been 

 carefully considered by many authors, notably Schwalbe (4, 8, 9), 

 Logan Turner (10), Biaiichi (11), Zuckerlandl (1"2) and Cunningham 

 (13). 



Cunningham considers that the relatio.iship which exists between the 

 sinus and glabella is a problem which must for the meantime remain 

 unsolved. 



As with the glabella, so also the position of the inion has been the 

 subject of considerable investigation. Keith (14), Klaatsch (15), 

 Sollas (3), Anderson (16), Rieger (17), Fraipont and Lohest {li^}, 

 Kramberger (19), and others, all agree that variations exist in the 

 positions of the external and internal protruberantia. 



