In Thomas Kinsella's "The Chrysalids," the speaker describes his or her "last free summer," a time when one can wake up at any hour (Stanza Three) or pedal slowly because he possesses no urgency to get anywhere quickly. While the literal definition of a chrysalid is the cocoon stage of a moth or butterfly, Kinsella's poem connects better with the figurative meaning of the word: a protective stage of development.
During the poem's glorious summer, after the speaker and his friends spend the day relaxing and exploring, they are greeted with "milk"--the chosen drink for developing humans--and he realizes that he was allowed
"to experience / A tolerance [he] shall never know again" (Stanza Four).
Kinsella uses the chrysalid time of life to demonstrate that humans often do not appreciate the wonders of their cocoon stage of life until they have left it behind. He contrasts this naivety with how the speaker and his comrads are greeted by adults. In Stanza Three, they are
"received with womanly mockery into the kitchen, / Like calves poking [their] faces in with enormous hunger."
The poet notes that adults respond with fondness and humor to the innocence and abandonment with which the speaker lives his life, encouraging him to take full advantage of it before it vanishes. The adult "moths" realize that they can never again return to the chrysalid state.