A CASE OF A SYNDACTYLOUS CAT 81 



margin of the hand plate (Broman, '04). To effect syndactyly 

 the pressure would have to be exerted laterally. There are two 

 chief difficulties in the way of such an explanation. If the am- 

 nion is the determining factor some evidence pointing to this 

 should have come to light (Broman, '04). The chief difficulty, 

 perhaps, is presented in the general symmetry of the abnor- 

 malities. It is difficult to see why the pressure, unless itself 

 the result of some physiological condition, should be effective 

 symmetrically. It is conceivable that lateral pressure might be 

 effective in causing a change in the normal shape of the early 

 limb pads, as was suggested above, but it is difficult to explain 

 the source of the pressure. 



Various other abnormalities are occasionally associated with 

 Polydactyly or syndactyly. No causal connection between 

 these defects has been established and they are of no significance 

 for the general condition under discussion. None of these 

 defects were present in the kitten. Bateson ('94, p. 399) finds 

 occasionally phocomely, cyclopia, double uterus, hare fip, de- 

 fective dentition, defect of tibia, associated with Polydactyly. 

 Lewis ('09, p. 10) finds Polydactyly occasionally in conjunction 

 with hare lip and abnormalities of the limb bones. Bateson 

 ('94, p. 399) finds syndactyly associated very often with general 

 deformity and with many forms of arrested development. 



JOURNAL OF MORPHOLOGY, VOL. 30, NO. 1 



