WHAT we are is in part only of our making ; the greater part of 

 ourselves has come down to us from the past. What we know and 

 what we think is not a new fountain gushing fresh from the barren 

 rock of the unknown at the stroke of the rod of our own intellect ; 

 it is a stream which flows by us and through us, fed by the far-off 

 rivulets of long ago. As what we think and say to-day will mingle 

 with and shape the thoughts of men in the years to come, so in the 

 opinions and views which we are proud to hold to-day we may, by 

 looking back, trace the influence of the thoughts of those who have 

 gone before. Tracking out how new thoughts are linked to old ones, 

 seeing how an error cast into the stream of knowledge leaves a 

 streak lasting through many changes of the ways of man, noting 

 the struggles through which a truth now rising to the surface, now 

 seemingly lost in the depths, eventually swims triumphant on the 

 flood, we may perhaps the better learn to appraise our present 

 knowledge, and the more rightly judge which of the thoughts 

 of to-day is on the direct line of progress, carrying the truth of 

 yesterday on to that of to-morrow, and which is a mere fragment 

 of the hour, floating conspicuous on the surface now, but destined 

 soon to sink, and later to be wholly forgot. 



SIR MICHAEL FOSTER, Hist, of Physiology. 



