ON HABITS OF OBSERVING. 39 



habits, in many instances, of animals in confinement, 

 or in a domestic state, are notorious. As regards 

 dates, of which the Naturalist's Calendar is almost 

 exclusively made up, they are liable to be influenced 

 not merely by season, but by many accidents affect- 

 ing the individuals to which they relate. Age, health, 

 sex, the interference of man, an unusual supply of 

 food of a particular kind in certain spots, the greater 

 or less prevalence of enemies, and several other 

 causes, may all operate in forwarding or postponing 

 any natural occurrence. Hence, if we desire to 

 arrive at the true law regulating any class of ob- 

 served facts, especially w r hen some of them appear to 

 deviate from the usual order of things, we should 

 carefully note down all the attending circumstances ; 

 all such at least as can by any possibility have any 

 influence over them. And herein it is much better 

 to be too diffuse than too meagre. We must guard 

 against thinking, in any doubtful point, that it can 

 be of no use to note this or that circumstance, for 

 we are not at the moment in a position to determine 

 its importance. This can only be decided afterwards, 

 when we or others shall have collected many such 

 parallel cases ; and we can see what circumstances are 

 common to them all, and what are evidently adventi- 

 tious in a few only. And if we neglect to register at 

 the time all that the eye notices, we may in the end 

 deeply regret the omission of many particulars, when 

 it is oujt of our power to supply the defect by any 

 fresh observation. For unlike the natural philos- 

 opher, who can often, by experiment, create for him- 

 self all the circumstances attending a particular 



