### Clue: Excessive amount found by academic about The Origin of Species? That's probable (4-2)
### Answer: ODDS-ON 
 ### Explanation: Definition: probable
 OD(abbrev. for "overdose"/an excessive amount, of, say, drugs) **plus**(found by) DON(an academic/a lecturer at, say, a university) **containing**(about) **1st letter of**(*The Origin of*) "*Species*".