674 
POLYDACTYL1SM TN THE CAT. 
directly to 6, the place of its usual division being occupied 
by a special small muscle. 
Thus, it seems from the myology of the region that 
1 is the extra digit, and results from proliferation of 
the pollex (2), a tendency of which in this direction 
is proved by the presence of the above-mentioned rudi¬ 
mentary digit. No. 1 is the smallest of the developed 
digits ; its metacarpal is very slight, but superiorly enters 
into the formation of the carpo-metacarpal joint, and is 
united to metacarpal (2). The joint between the first and 
second phalanx is anchylosed, and the union between the 
latter and the ungual phalanx is incomplete. Altogether the 
general rudimentary condition of this digit confirms the 
above opinion* Thus, we must consider as correlated varia¬ 
tions those characters, which we have above noted, as 
seeming to indicate that 6 is the superadded digit. 
Hind foot. 
Each hind foot has six well-developed digits, which may 
be designated, from within outwards, 1, 2, 3, 4, 5, and 6; of 
these 6 is small, but 1 is smaller. The palmar pad is com¬ 
posed of several lobes arranged in series, increasing in size 
from within outwards to the largest, opposite Nos. 4 and 5, 
externally to which is a medium-sized lobe. Each digit 
bears a digital pad corresponding directly wdth its size; also 
each bears a well-developed claw. 
Muscles. 
Tibialis antieus consists of two parts :—a, with short, stout 
tendon, terminating at supero-anterior part of metatarsals 1 
and 2 (of which the division to 2 is much the smaller) ; /3 
forms the main extensor tendons passing to ungual phalanges 
of 1 and 2. 
Extensor longus communis digitorum is attached by its 
terminal tendons to 3, 4, 5, and 6. 
Flexor digitorum perforatus runs by its terminal tendons 
to all the digits, except 1. 
Flexor digitorum perforans terminates inferiorly by six 
stout divisions, one running to each digit; it receives the 
well-developed tendon of one of the divisions of flexor 
accessorius below and behind the tarsus. 
Tarso-prephalangeus has four tendons passing to act as 
accessory extensors to digits 2, 3, 4, and 5. 
Analysis of muscular variations. 
Nos. 1 and 2 seem to represent a double hallux. Thus, 
