716 REPORT—1904, 
Two important sw/ci are to be seen. That which is more anterior in situa- 
tion corresponds to the Bogenfurche of His; the second and more posterior 
sulcus seems to represent the calearine, or possibly the paracalcarine, element. 
The problem is to solve the question as to the nature of these sulci, 
ae. whether they are natural, or simply due to decomposition. In the human 
cerebrum, it is generally conceded that the Bogenfurche is an artificial product, 
though I believe that His did not admit this. As to the calcarine suleus, the 
tendency is to consider it as naturally present at a very early period. In the 
gorilla brain shown I see no means of discriminating between the two sulci; 
but considering the occasional late appearance of the calcarine sulcus, as shown 
in one of Cunningham’s figures, it seems as though both should be regarded as 
of artificial origin. It remains to note that Professor Retzius is of opinion that in 
this gorilla brain the calcarine eudeus is, so to speak, ‘ genuine.’ 
3. Some Variations in the Astragalus. By R. B. Seymour Sewe tt, B.A. 
_ The bones examined number upwards of 1,000 and are mainly of Egyptian 
origin. 
‘\s regards the angles which the collum makes with the corpus these speci- 
mens are intermediate between the Europeans and the anthropoid apes, The 
adoption of certain postures produces changes in the articular surfaces; thus in 
squatting we have a formation of facets on the neck, and in the sartorial position 
we get changes in the facies malleolaris medialis and a formation of an accessory 
facet, facies accessoria externa, 
he process of eversion of the foot has also caused structural changes in the 
bone, certain specimens from Borneo being intermediate between the Egyptian 
and the anthropoid apes. : 
Occasionally we find accessory facets present. The facies accessoria inferior 
may be fused with either the facet in front or behind, and in rare cases with both. 
We occasionally tind the middle and posterior calcaneal facets fused directly ; 
and in rare cases the anterior calcaneal facet is absent. The os trigonum is 
very variable both in size and shape; usually it takes no part in the formation of 
the sulcus musculi flexoris hallucis longi, but in very rare cases this groove 
may be formed either partly or entirely by this ossicle. 
4. Some Varieties of the Os Calcis. By P. C. Laiwiaw. 
_ From the collection of bones in the Cambridge University Museum I have 
picked out a number which present variations of an interesting nature, 
The varieties I have chosen fall under six heads :— 
(1) The variability of the processus trochlearis seems to show that it is not 
developed from a separate ossicle, as Professor Pfitzner suggested. 
(2) The external plantar tubercle. 
Its variations in man, its absence in the anthropoids and its probable develop- 
ment, the anatomy of the soft parts in man and the chimpanzee, show that it is 
a structure developed for the more ready maintenance of the upnght position. 
(8) Calcaneus secundarius of Gruber. 
(4) Os sustentaculi proprium. 
_ (5) The processus trochlearis of Kyrtl and its variation seem to show that it 
18 not necessarily pathological. 
(6) Variations in the facets met with in the bone— 
Due to (a) ossicles, 
(6) Other factors. 
The projection of the heel is more limited in Europeans than in the ancient 
Hgyptians owing to backward extension of the fascia articularis posterior. 
