Karl Pearson and Adelaide G. Davin 
155 
The bearing of the whole of this paragraph on Gruber's Uiter work is important, 
and it is regrettable that he did not give more consideration to its statements. 
The exact position of affairs with regard to the sesamoids of the knee-joint in 
man in 1872 was as follows : 
(i) The erroneous statement of Vesalius, at once corrected by Eustachius, had 
been more or less discarded, even in the text-books. 
(ii) The existence of the lateral fabella in man was recognised as a not 
uncommon occurrence and it might be an orthosesamoid or a hemisesamoid. If the 
latter it was described as " fibro-cartilaginous." 
(iii) The existence of the mesial fabella was realised to be something much 
rarer, and less often an orthosesamoid. It was, however, vouched for by such 
credible observers as Eustachius, Morgagni, Sommering, Hyrtl and Macalister, and 
by the less credible Heister. 
(iv) There was a growing realisation that in man the fabella lateralis had 
relationship not only to the tendon of the outer head of gastrocnemius, but to 
M. plantaris (Cheselden and Sommering) and to the posterior ligament of the knee- 
joint (Humphry). 
(v) Camper had discovered the cyamella lateralis in the orang as a persistent 
feature, although the fabellae are absent. He had found it accompanied by the 
fabella lateralis in certain of the lesser apes, and such association is invariable in 
the cat*. There was really no excuse in 1872 for confusing the lateral cijamella 
with the lateral fabella. While Camper denied the existence of the cyamella in 
man, Macalister had discovered it as a rare anomaly. 
(4) History of the Sesamoids of the Knee-Joint. Second Period — t^iat of Mono- 
graphic Literature. 
The three chief memoirs to be now considered are those of Gillette (1872), 
Gruber (1875) and Pfitzner (1892). Of these authors Gillette and Pfitzner consider 
all the sesamoids of the human skeleton, Gruber only those of the knee-joint, and 
of these he realises only the fabellae. 
(a) Gillette's paper is entitled " Des os sesamoides chez I'homme," Journal de 
I'Anatomie et de la Physiologie, pp. 506 — 538, Plate XX, Paris, 1872. Gillette 
commences by dividing sesamoids into peri-articulaires and intra-tendineux — this 
distinction is not without its uses. He says, however, that the first are true bones 
and the second are not (p. 535). He admits, however, when he comes to the 
fabellae, which clearly are intratendinous, that they, apparently because they 
are more voluminous, have greater resemblance to the periarticular sesamoids. 
He gives in his Fig. 16 the first really good illustration of the fabella lateralis in 
situ. We have reproduced it in our Plate I, Fig. 3. 
* See Mammalian Anatoiiiij of Horace Jayne, Loudon and Philadelphia 1898. Part i. The Skeleton 
of the Cat, pp. 704—5. 
