It derives from the pet name Atkin, which is a diminutive of Adam. In Scotland the name is more usually rendered as Acheson, while it is more usually found rendered as Atkinson in England, where it is particularly common in the north.
By the time babies are between 9 and 12 months old, they're often ready to make the switch from bottle to cup. At this age, they're more interested in what's going on around them than they are in sucking on a breast or bottle. But phasing out the bottle this early means planning ahead. Here are some tips:
Between 6 and 12 months, as your baby eats more solid food, the amount of formula or breast milk he drinks will naturally decline. So yes, he may drink less as he figures out how to use his sippy cup, but he'll probably also take a keener interest in his jarred peaches -- which is totally normal.