What is referred to by 'by the fact itself'?

Based on the clue 'by the end of this era the last trilobite bit the ...', what is the answer? Based on the clue 'by the end of this jm barrie play wendy flies so b...', what is the answer? Based on the clue 'by the end of this scottish play the title charact...', what is the answer? Based on the clue 'by the end of this sigmund romberg operetta the ti...', what is the answer? What is associated with: by the geneva accords of 1954 the 17th parallel divided this asian nation into northern southe… What is associated with: by the late 1530s the spaniards had completely conquered this indian empire? Based on the clue 'by the looks certainly the smell of them the herd...', what is the answer? What is associated with: by the mid 1950s this country had about 375 subs in various oceans seas?