156 
On the Sesamoids o f the Knee- Joint 
Gillette (p. 533) asserts that in the foetus and the child there are no traces of 
the fahellae. This is, of course, opposed to Nesbit's conclusion, but as in perhaps 
nine cases out of ten no trace of the fahellae can be found in the adult, his 
assertion is like Gruber's by no means conclusive*. Gillette is a strong supporter 
of the intensive stress theory of the origin of sesamoids. He asserts that little by 
little : 
par le frottement le tendon s'elargit, .s'aplatit, devieut plus dense. II se produit h, ce niveau et 
dans son epaisseur un ^paisaement d'abord fibro-cai'tilagineux, c'est I'os sesamoide intra-tendineux 
cartilagineux, mais sous certaines influences toujours de nature mdcanique, il se depose des 
molecules osseuses dans I'interieur de ce noyau qui se constitue os sesamoide osseux (p. 534). 
The argument seems to us of precisely the same character as the argument 
that the environment produces the plant. In a certain sense it does, bixt the seed 
contains the potentiality of the plant. We might argue that nourishment and 
exercise produce the human skeleton, and it is oidy in this sense, that the fabella 
is no moi'e the product of mechanical causes than the femur itself, that we 
can accept Gillette's statement. We believe, however, that both he and other 
supporters of the theory of intensive stress mean a great deal more by it than we 
are willing to admit. Some decision might be made by the examination of the 
puppy in various stages of growth, we should be much surprised, if the intense 
activity and restlessness of a young puppy could be subdued, to find it growing up 
without or oven with much diminished fahellae ! 
The classification of sesamoids into intratendinous and periarticular is con- 
venient, but to identify these with hemisesamoids and orthosesamoids seems to us 
extremely doubtful, and to state that the former pass into the latter owing to 
mechanical causes we do not find at all helpful. 
(h) Gruhers MonograpJff : This memoir exhibits all the surpassing merits 
and some of the small but disturbing faults of this eminent anatomist. It 
presents Gruber's usual wealth of new material and his extensive knowledge of 
earlier literature. We have at once a sweeping clearance out of all the old 
anatomical myths, and the forcible statement of new and sounder ideas based 
on wider ranges of observation. For the first time in the history of our subject we 
have adequate material directly examined and recorded. Again for the first time 
we have a real attempt made to record the appearance or non-appearance of the 
fahellae in vaiious living forms. We begin to realise at once that as in the case 
of man, so in the case of many other living animals the contradictions of earlier 
writers chiefly arise from want of adequate material ; the problem is not whether 
fahellae do or do not exist, but in what proportion of cases they will be found. In 
* It is needful to take a case where a, fabella always occurs, e.g. the dog, and when Gruber dissected 
puppies he did find tho fahellae prefigured. We have repeated this observation, and we have also found 
that tlie kitten at birth prefigures the lateral /afcf /to and cyamclla by nodules of hyaline, not fibrous 
cartilage. 
•f " Monograjshie iiber die aus wahren (byalinschen) cartilagines praeformirten Ossieula sesamoidea 
in den Ursprungssehnen der Kopfe des 71/. gastrocnemius bei den Menschen und bei den Saugetbieren." 
Memoires de VAcademie imperiale des Sciences de St Pitersbourg, VIP S6rie, Tome xxii, 1875, No. 4. 
