378 MERISTIC VARIATION. [part i. 



endowed with individuality be not of universal application, we shall 

 not save it even if by ingenuity we may represent the facts of the 

 present case as in conformity with its conditions. 



On the other hand it may be suggested that there is a division 

 of some one digit, and undoubtedly in No. 559 there is a sugges- 

 tion that the innermost digit and the central digit are both formed 

 by division of III. But in the first place this view cannot so easily 

 be extended to Nos. 557 and 558, for in them there is practically 

 no indication that the digits are not all independent and equivalent. 

 The circumstance that the nutrient vessel enters between the 

 external and middle digits may perhaps be taken to shew that 

 they are III and IV ; but this vessel, if single, must necessarily 

 enter in one or other of the interspaces and there is no reason for 

 supposing that, were there an actual repetition of a digit, the 

 vessel must also be doubled, though doubtless repetition of vessels 

 commonly enough occurs with repetition of the organs supplied. 



Next, the Symmetry of the foot, the development of the middle 

 digit to take a median place, the position of the accessory hoofs, 

 one on either side equidistant from the middle line of the manus, 

 all these are surely indications that this limb was from the first 

 developed and planned as a series of three digits, and not as a series 

 of two digits of which one afterwards divided. The series has a 

 new number of members, and each member is in correlation with 

 the existence of the new number remodelled. 



It is no part of the view here urged to deny that a single digit, 

 like any other single member of a series, may divide into two (or 

 even into three) for this phenomenon is not rare. Probably enough 

 No. 559 is actually a case of such a division of the digit III. But 

 here in digits as in mammse, teeth, &c, the evidence goes to shew 

 that there is no real distinction between the division of one member 

 to form two, and that more fundamental reconstitution of the series 

 seen in No. 557, for the state of No. 558 is almost halfway between 

 them. In it we almost see the digit III in the act of losing its 

 identity. 



(2) Limbs with digits in two systems of Minor Symmetry (Double-foot). 



In dealing with these there are difficulties. The cases are examples 

 of limbs of Calves or Sheep bearing four or five digits arranged in two 

 groups either of two and two, or of two and three. The members of 

 each group curve towards each other in such a way that each group 

 has a separate axis of Symmetry (Figs. 117 and 118). In several such 

 cases the two groups are related to each other as right and left. Of 

 these facts two different views are possible. For first, a limb of this 

 kind may be a structure like the double-hands seen in Man (pp. 331 to 

 337), for it is certain that an almost completely symmetrical series of 

 parts is in those cases formed by proliferation of a series normally 

 hemi-symmetrical, however unexpected this phenomenon may be. 



On the other hand it might be argued that one of the groups of 

 digits represents the normal, and that the other group is supernumerary. 



