80 
Froceedings of the Roijal Irish Academy. 
tlie tendinous slip was lost on tlie dorsum of the fifth metatarsal bone 
and the fascia which covers the fourth dorsal interosseous muscle. 
There cannot be a doubt that Pozzi, and also Wood in his first 
statistics, altogether understate the frequency of occurrence of the 
peroneus quinti digiti in man. Testut expresses a similar view in his 
remarkable work, entitled ' Les Anomalies musculaires chez homme." 
He says with reference to the results obtained by these authors : " Ce 
rapport est bien evidemment trop faible, si Ton tient compte de tons 
les cas ou un tendon surnumeraire se detache du tendon du court 
peronier lateral pour se terminer sur n'importe quel point de la region 
tarso-metarsienne." 
The more recent statistics of Wood more nearly express the truth, 
and in these he distinctly records all forms of the muscle, both rudi- 
mentary and well-developed ; still they fall considerably short of the 
results obtained by us. Perhaps an average struck from both would 
yield the most accurate result. This would give 60 cases in which it 
was present out of 147, i. e. 40 per cent. 
But the peroneus quinti digiti is not always found in this very 
rudimentary condition. In the forty -five subjects examined it was 
observed on two occasions to be provided with a fleshy belly. In one 
instance this fleshy belly was only partially blended with the peroneus 
brevis. It arose in the leg from the septum which intervenes between 
the peroneal group of muscles and the muscles on the posterior aspect 
of the leg, and its tendon turned round the external maleolus in the 
peroneal sheath, and finally found insertion into the tendon of the 
common extensor which goes to the little toe. Such a condition is not 
unknown. Macalister * has also described such a muscle. Here, then, 
is an example of the extensor brevis minimi digiti reverting to its 
original separate condition, and asserting its primitive independence. 
In the second case the muscle arose by a tendionous slip from the 
tendon of the peroneus brevis as it turned round the external maleolus. 
This gave place to a fusiform fleshy belly which was situated on the 
dorsum of the foot, on the outer side of the extensor brevis digitorum, 
and closely connected with it by areolar tissue. It finally ended in 
a slender tendon, which presented the usual insertion on the dorsum of 
the little toe. Similar cases have been recorded by Hallet,^ "Wood,^ 
* " Muscular AnomaHes in Human Anatomy" — Trans. Boy. Irish Acad., vol. 
XXV. (Science), p. 133. 
5 Hallet, Edin. Med. and Surg. Journ., 1848. 
^ Wood, Proc. Roy. Soc, vol. xvi. 
