316 MEBJSTTC VARIATION. [part I. 



relations to the tarsus which an index should have. The tarsus is 

 as in the last Condition. 



In the specimen seen, c 1 and c 2 were not actually separate from 

 each other, but there was a distinct line of division between them. 



Here then the digits enumerated from the external side are as 

 follows : — 



Bight. Eight. Eight. Left. Left Hallux-like 



V IV III II digit digit 



IV. The stage next beyond the last is shewn in Fig. 87, II. 

 [The drawing is from a left foot.] Here there are six digits, each 

 with three phalanges. The three externals are normal and true 

 rights as before. The other three are all formed as lefts. Tarsus 

 as before. 



This foot may be represented thus : — 



Eight. Eight. Eight. Left. Left Left 

 V IV III II digit digit 



As far as I have seen the last or fourth Condition is the com- 

 monest. There are doubtless many variants on these plans. 

 No. 477 is an especially noteworthy modification of the third 

 Condition and the cases of the hind feet in No. 478 must also 

 be specially studied as not conforming truly to either Condition. 



Forefoot. 



I. The normal right fore foot has four digits II — V each with 

 three phalanges all differentiated as rights, and a pollex with two 

 phalanges, the last being non-retractile but bearing a claw. It may 

 be represented thus : — 



Eight. Eight. Eight. Eight. Pollex. 



V IV III II I 



Departures from this normal are more irregular than they are 

 in the case of the hind foot. Those given in this summary being 

 only a selection. For the others the evidence must be examined. 



II. One specimen, No. 474, has the four external digits normal. 

 The pollex however has three phalanges and is formed as a digit of 

 the other side, thus : — 



Eight. Eight. Eight. Eight. Left. 



V IV III II I 



III. The next Condition seen was as follows : — 



Eight. Eight. Eight. Eight. 



V IV III II 



cS "S S 



CD ^t 03 



^ IS ft 



Left Indifferent 



digit digit 



IV. In the majority of polydactyle cats the manus has the 

 digits II — V normal in shape and symmetry. Internal to the 

 digit II are two digits more or less united in their proximal parts ; 

 sometimes the metacarpal only, sometimes the metacarpal and first 

 phalanx are common to both. Of these two digits the external, 



