| Answer | Crossword Clue |
|---|---|
| ORIGIN | Darwin's "On the ... of Species" |
| ORIGIN | Darwin's "The .. of Species" |
| ORIGIN | Darwin's "The ... of Species" |
| DARWIN | "On the Origin of Species" author |
| DARWIN | "On the Origin of Species..." author |
| FACTIOUSBOOK | "On the Origin of Species," for one? |
