1.^8 
On the Sesamoids of the Knee-joint 
orthosesaraoids ("sesambeine") and hemisesamoids ("sesanioide") ; the latter he con- 
siders develop in fibrous cartilage ("faseriges Gewebe") and do not ossify*. Hemi- 
sesamoids are abortive sesamoids ; we may term them vestiges of past phases of 
evolutionary development. Pfitzner does not, however, attempt to follow up the 
view here suggested by the examination of sesamoids in a large number of types 
other than man. Man is of course the subject of his paper, and the sesamoids of 
the knee-joint with which we are at present interested form only one element in 
his monograph. 
The keynote, however, of Pfitzner's suggestion that hemisesamoids are not 
necessarily orthosesamoids in the making, but may be the evolutionary debris of 
what have been orthosesamoids, vestiges of ossilicatory centres where no ossification 
now sets in, is well worth bearing in mind. It is not incompatible with sesamoids 
appearing in regions of intensive stress, for it is possible that in such regions the 
sesamoid or its precursor would be of special value to the organism. 
(2) Origin of the term Sesamoid. 
The term sesamoid is not to be found in any author previous to Galenf, but he 
uses it in the sense of a word f;xmiliar to his readers. It is probable that Galen 
only knew the sesamoids of hand and foot. He does not directly refer to tliose of 
the knee-joint. Eu.slachius in 15G4 argued that Galen must have dissected the human 
cadaver and not those of monkeys J, because he does not refer to the fahellae, but 
as Galen clearly considered sesamoids of no great importance, he may simply have 
omitted reference to them. If he dissected carefully a considerable number of 
human bodies, it is singular that he should not have met with the fabellae occasion- 
ally, but the same criticism applies to all anatomical writers up to Vesalius (1555). 
We have been able to discover four passages, three in the accepted, one in the 
spurious books of Galen, referring to sesamoids. We cite from the Latin translations. 
* This does not seem in accordance witb Gruber's view (see our pp. 157 and 175), that sesamoids 
are invariably prefigured by hyaline and not fibrous cartilage. 
t Galen was born at Pergamum a.d. 131. He went to Kome and was known to Marcus Aurelius. 
He died aged 70. 
J " Adaiiratione denique obstupui, cur anatomiae iustauratores, in secunda libri de hominis fabrica 
editione, nbi administrationem musculorum pedis docent, duo ossicula magnitudine ciceris describant, 
quae supra utrumque femoris tuberculum reperiuntur, qua nimirum primi duo pedem moventes oriuntur 
musculi: nam & si ea in simijs & in canibus semper occurrant, in hominibus tamen adeo raro inueni- 
iintur, ut nou modo (quod posteriores addiderunt) saepius alteram, nunc internum, nunc externum 
deficiat, uerum etiam ut plurimum utrumq: ipsorum desit, miraculum enim existimabo si duo simul 
occurrent, & non mediocri diligentiae ascribam, si post multorum cadaverum sectionem alterum illorum 
quis inveniat. ideo que tantum abest, ut aequum sit eiusmodi ossicula inter hominis partes numerare, 
ut etiam liceat suspicari ea a Galeno consulto fuisse pretermissa, indeque sumere argumentum tantum 
anatomicae artis praeceptorem homines non simias nobis descripsisse. Addo sine aliquo fructu laborare 
illos, qui comnientitias quasdam utilitates horum ossiculorum contingunt: neque enim natura, quae 
provida est & omnium opportunitatum moderatrix, veretur ne in cruris directione principia paulo ante 
memoratum musculorum comprimantur & atterantur. Si enim hie esset eius scopus in illis conformandis 
multo magis in homine, quam in simia & cane reperirentur, quando horum uterque longe minus, quam 
homo tibiam ambulando extendit." 
See Bartholomaeus Eustachius, Opuscula Anatomica, Venice, 1-564, p. 180. 
