c7f1ccc7___open_books_for_an_open_world__Response
[Reflex] Sucking [Stimulation] Place fingers in infant's mouth. [Age of disappearance] 4 months (voluntary sucking will come about) [Function] This helps with feeding. [Response] 
The infant will suck finger rhythmically.
Human Physiology/Print Version - Wikibooks, open books for an open world