FRUSH. 435 



preventing any dislocation between them, at the same time 

 admits of such motion between the one and the other as is 

 requisite for the play or performance of the functions of their 

 several respective parts during the time the animal is in action. 

 But motion of no kind, however limited, can go on, especially 

 between organized and inorganized parts, without lubrifaction of 

 some sort; and this is, in the instance in question, provided for by 

 a peculiar sebaceous kind of secretion known to us more per- 

 haps by peculiarity of odour than by any other property it may 

 possess. This secretion naturally escapes through the pores of 

 the horn into the cleft of the frog, where it becomes absorbed 

 and disappears. Should it, however, from irritation or inflam- 

 mation of the parts secreting it, become so redundant in quan- 

 tity as to give rise to the appearance of moisture in the cleft, 

 and perceptible smell likewise — and it never does so without 

 undergoing at the same time alteration in quality — the dis- 

 charge of it constitutes frush. Coleman used to compare this 

 secretion to the exudation taking place between the toes of our 

 own feet, to prevent them growing together ; and, no doubt, 

 some similar purpose is answered by it in the cleft ; though I 

 would rather make a comparison between the secretion in the 

 axilla of man and that in the cleft of the frog, seeing that there 

 is something in both instances beyond mere exposed superficies. 

 Bracy Clark has represented frush to be a fracture of the 

 frog-stay ; and has distinguished it into natural and secondary 

 or acquired. " The frog-stay," he says, is " the last of the foot 

 in obtaining its perfect growth and consolidation — being in some 

 perfected at two years and a half, in others not until three and 

 a half or four; and, if opposed by natural weakness or exter- 

 nally destructive agents of the horn, such as wet, dirt, urine, 

 &c., then the frog will never be properly closed, and a frush 

 will be the consequence through life*.'' In proof of which 

 opinions being founded in fact, he gives an account of having 

 visited some colts belonging to the East India Company at 

 pasture near Epping Forest, and finding several among them 

 with frushes : a circumstance plainly explicable in my mind by 



* See his " Essay on Running Frush." 



