Kay Ryan is not interested in formal rhyme schemes, but she's famous for her virtuoso manipulation of slant rhyme (in which the matching sounds are approximate rather than precise) as well as her brilliantly selective use of exact rhyme. In "Turtle," she uses slant rhyme throughout the poem to knit together sounds and ideas. In most cases, the slant rhymes are internal rhymes, as she rhymes words that are embedded within lines rather than words at the ends of lines (terminal rhyme).
Ryan likes internal rhyme so much that she coined her own term for it—"recombinant rhyme"—and compares it to cutting-edge genetic research. Say what? "It's like how they add a snip of the jellyfish's glow-in-the-dark gene to bunnies and make them glow green," muses Ryan. "By snipping up pieces of sound and redistributing them throughout a poem I found I could get the poem to go a little bit luminescent."
Examples of internal, slant rhyme in "Turtle" include "graceless" and "places" (5-6), "slope" and "hopes" (6-7), "ditch" and "dish" (10-11). Notice how the rhyming words call attention to the turtle's vulnerability. The poem also includes some terminal slant rhyme, for example "practical" and "optimal" (8-10). Together, these two words imply a logical frame of mind, a reliance on commonsense calculations to get by in life.
But wait, that's not all! Kay Ryan loves rhyme so much that she even employs the more unusual technique of mosaic rhyme, in which one word rhymes with the sound unit formed by two or more other words. In lines 1-2, "helmet" and "help it" form a mosaic slant rhyme. In lines 2 and 3, "afford" and "a four-oared" create an even fancier mosaic slant rhyme. How cool is that! So cool that Kay Ryan actually identified it as "my favorite all-time rhyme."
After teasing us with all that "almost" rhyme, Ryan uses exact rhyme on four occasions in "Turtle." In the opening line, she gets our attention by rhyming "would" and "could." In line 10, she sneaks in the sly rhyme "ditch which." In lines 12 and 13, she rhymes "lottery" and "pottery." Three-syllable rhymes are usually reserved for humorous verse, but Ryan sneaks in a serious idea here by contrasting the turtle's humble circumstances (pottery) to unattainable riches (lottery). Finally, Ryan unleashes the full power of terminal exact rhyme in lines 13 and 15: the evocative word "wings" rhymes with "things," the last word of the poem, creating a strong sense of emotional closure.
But wait! We haven't even talked yet about assonance (repetition of vowel sounds) or alliteration (repetition of beginning consonant sounds)! Ryan makes full use of these sound-based poetic devices as well as rhyme. Examples of assonance in "Turtle" include "practical" and "axle" (7-8) and "convert" and "serving" (10-11).
As for alliteration, check out "hard" and "helmet" in line 3 or "packing-case" and "places" in line 6 or "pottery" and "patience" in lines 14-15. But Ryan doesn't stop at using alliteration for two words. Just as she uses rhyme to knit the poem together, she uses alliteration to forge connections among multiple words and lines of verse. For example, lines 3-5 gain unity from the repetition of words beginning with "T" ("take," "toward," "track"). And for a real whacko-socko demonstration of alliteration, check out lines 11-14, where five words begin with the letter L: "lives," "luck-level," "lottery," "load," and "levity."
All this sound-stitching creates a dense, interwoven sonic effect in the mind's ear (if you can picture that)—a little like a tight, protective shell, we'd say. Hmm. We wonder what animal that might remind us of!