CHAPTER XVII 



THE BULL ONTHOPHAGUS: THE CELL 



"OEGUN to-day and dropped to-morrow, 

 -■-* taken up again later and again aband- 

 oned, according to the chances of the 

 day, the study of instinct makes but halting 

 progress. The changing seasons brings un- 

 welcome delays, forcing the observer to wait 

 till the following year or even longer for the 

 answer to his eager questions. Moreover, 

 the problem often crops up unexpectedly, as 

 the result of some casual incident of slight 

 interest in itself, and it comes in a form so 

 vague that it gives little basis for precise in- 

 vestigation. How can one investigate what 

 has not yet been suspected? We have no 

 facts to go upon and are consequently unable 

 to tackle the problem frankly. 



To collect these facts by fragments, to 

 subject those fragments to varied tests in 

 order to try their value, to make them into 

 a sheaf of rays lighting up the darkness of 

 the unknown and gradually causing it to 

 emerge: all this demands a long space of 



