DICHOTOMY. 113 
Dichotomy may, not infrequently, affect other digits ; 
thus in fig. 61 a chick is represented with two bifid 
toes and partial duplicity of the left leg. Birds with 
these accessory parts may live and attain the adult 
condition. 
Supernumerary legs are very common in birds, indeed 
Tic. 61.—A Chick with two dichotomized digits 
and a supernumerary leg. 
almost every poultry breeder has seen examples, yet 
accessory wings are very rare. One specimen only is 
known to me, a dove, preserved in the museum of the 
Royal College of Surgeons (fig. 62). This bird has an 
accessory wing growing from the lower part of the 
sternum, 
No) 
