Karl Pearson and Adelaide G. Davin 
151 
muscnloriim hominis and other works), 1734 — 1757, have no reference to the 
fahellae. Palfin (Anatomie cinrnrgicale...du corps hmndiii, Vol. li, p. 159), 1726 — 
1734, says they are not always to be found as Vesaliiis believed, while Winslow 
{An Anatomical Exposition of the Structure of the Human Body, London, 1749, and 
Exposition anatomique de la structure du corps humain, Paris, 1732) apparently con- 
siders they are always to be found, and in cartilage-lined hollows. George Thomson 
{Anatomy of Human Bones, London, 1734, p. 104) asserted the existence of both, 
which was the view taken by Kulrnus in his Tabulae anatomiae (p. 62) of 1732 and 
supported by the authority of Haller in 1745. In such a sea of wearisome positive 
and negative assertions unaccompanied by personal examination, it is almost a 
comfort to meet such a bare statement as that of Drake in his Anthropologia nova, 
3rd edition, 1750, p. 434: 
There are sometimes found two ossa sesamoidea in the two beginnings of the Gastrocnemius 
externus muscle, but they are rarely met with and only in aged Bodies. 
He at least knew that they did not always occur or fail to occur, even if he 
supposed no difference in frequency of the pair. Still more comforting is Morgagni's 
statement {Adversaria anatomica, T. ii, Leyden, 1723, p. 64*) that he had found 
the lateral fabella several times, but the mesial fabella only once. It goes at any 
rate a little way to balance the statements of Lieutaixd (1742) that he had found 
fabellae, more often mesial than lateral, of Disdier (1745) that one usually exists 
in the groove behind the lateral condyle, of Lauth (1798) that he had never found 
any fabellae, and of Bertin (1783) that he had found two on each femur ! 
How strikingly barren these 18th century anatomists seem to have been, at 
least in this matter of the knee-joint ! It is not till the very end of the centuiy 
that with Sommering and Peter Camper we get some progress in our pi'oblcm, and 
we begin again to grasp the difference between big and little naturalists. We will 
take the former first because his contribution is less important than those of Camper. 
Sommering {Vom Bau des menschlichen Korpers, Leipzig, 1791, Bd. ill, S. 295) 
recognised that a fabella is not infrequent in the lateral head of M. gastrocnemius. 
He continued to study the subject, however, and in his Lehre von. den Muskeln of 
1841, S. 347 — 351, he recognised that the lateral fibella is often only a hemi- 
sesamoid, i.e. cartilaginous, and that the mesial fabella is very rare, and when it 
does occur is far more likely to be a hemisesamoid than an orthosesamoid. Further 
like Cheselden (see our p. 150) he recognises a relation of the lateral fabella to 
M. plantaiHs : 
Der Ursprung des M. plantaris hangt mit der Ursprungsehne des lateralcn Uastrocnemius- 
Kopfe.s, namentlich auch mit dessen Sehnenbeiuchen eng zusammen. 
We are clearly in touch with a man, who is observing and thinking on his own. 
Peter Camper's first contribution occurs in his Dissertatio de fractura patellae 
et olecrani, Haag, 1789, translated as Abhandlung von Bruch der Kniescheibe und 
* His words are: " No.s certe (juod alterum eorum in nonnuUis cadaveribiis et iu uno internum 
nominatim invenisse meminimus." They do not occur in the edition of 1714 but will be found in the 
Venice edition of 1782. 
10—2 
