Brain has generously invited me to make a definitive study of the specimen 

 in question, but at the time of writing I have not yet made this study. Nor 

 have I yet made a third and independent estimation of the capacity. For 

 the moment, it would seem to be safest to choose an intermediate value, 

 namely 500 c.c, between Brain's and Holloway's estimates as an approxi- 

 mation to the total capacity of the Swartkrans specimen. 



The value of 500 c.c. (or even that of 530 c.c. and a fortiori of 475 c.c.) 

 lies within the sample range given by me for the gracile australopithecines 

 (435 to 54° cx -)- This is the first and thus far the only reliable estimate of 

 the crania] capacity from a South African site yielding robust australo- 

 pithecines. However, it must not be overlooked that the same site, Swart- 

 krans, has yielded a second hominid, which has been identified as a member 

 of the genus Homo and was originally called Telanthropus. To which of 

 the 2 Swartkrans hominids the new endocast belongs must for the time 

 being remain an open question, although it is tempting to infer that its 

 relatively small volume would tend to align it with Australopithecus rather 

 than with Homo. 



Olduvai. The hominid cranium found in the lower part of Bed I, 

 Olduvai Gorge, has been described as a hyper-robust australopithecine, 

 A. boisei (Tobias 1967a), formerly designated Zinjanthropus (Leakey 1959) 

 (Figure 12). No natural endocast was found with the cranial remains of 

 this Old. Horn. 5 specimen. However, enough of the endocranial surface of 

 the calvaria was preserved to make possible the preparation of a plaster 

 endocast (Figure 3). This was effected by me, with the invaluable expert 

 assistance of Mr. A. R. Hughes (Supervisor of Laboratories in the Witwaters- 

 rand Department of Anatomy) and Mr. T. W. Kaufman (formerly of the 

 staff of the same department). Approximately the posterior two-thirds of 

 the braincase was virtually complete; likewise the calvarial parts related to 

 the frontal poles and rostral regions. The areas between had to be recon- 

 structed. There is little doubt as to the intervening distance because of a 

 satisfactory approximation of the anterior and posterior calvarial parts. 



On the basis cranii the gap includes the anterior part of the middle 

 cranial fossa and most of the anterior cranial fossa. Thus, the precise extent 

 of the temporal lobes of the endocast and the exact position of the tem- 

 poral poles could not be determined from the surviving cranial bones. A 

 guide to these points is provided by the body of the sphenoid, most of 



3* 24 



