RUDIMENTARY STRUCTURES. 237 



they are found and those in which the kindred struc- 

 tures were functional. 



With the advent of the doctrine of evolution, and the 

 more careful investigations into the structure of animals 

 which had by that time taken place, a total change of 

 view as to the real nature and import of these so-called 

 rudimental structures at once ensued. Thus it was 

 soon found (not by conjecture, but from actual circum- 

 stantial evidence) that, in place of being the beginnings 

 of structures which eventually became functional, these 

 rudiments were really the remnants of structures which 

 had once been functional but had now become useless. 

 This change of view necessitates, therefore, that the 

 term " rudiment " in zoology must, at least very gene- 

 rally, be used in precisely the opposite sense to the 

 one in which it is employed in ordinary parlance. 



In order to make this application of the term quite 

 clear, we may mention one or two illustrations taken 

 from our own dress. For instance, at a time when 

 people wore elastic-sided boots more frequently than 

 they do now, the fronts of the boots were often orna^ 

 mented with a set of " dummy " laces and lace-holes. 

 These " dummy " laces being quite useless were, there- 

 fore, essentially rudimentary structures, which had 

 been, so to speak, retained as an ornament. Again, 

 the small black patch at the top of a judge's wig is 

 the last remnant of his black cap or hat, and is, there-* 

 fore, a useless rudimentary structure. Another case 

 is afforded by the little pocket-like fold at the end of a 

 university hood, which really represents the peak of 



