Lines 10-21 Summary

Get out the microscope, because we’re going through this poem line-by-line.

In the shade of the banks. Here, every spring
I would fill jampotfuls of the jellied

The speaker collects the frogspawn in jam jars—don't worry, not to eat.
The season has been cleared up for us. It's every spring that this happens. Spring is a time of rebirth and renewal, and that works in this poem where frogspawn is all over the place. Little slime balls are busy growing into frogs.
It seems that the speaker is having a little fun in line 11 with jam and jelly. We wouldn't want this jelly anywhere near our toast!

Specks to range on window-sills at home,
On shelves at school, and wait and watch until

"Specks" is still referring to the clumpy jelly in the jars. The little specks are the tiny beginnings of frogs held together in the goo of the frogspawn.
The speaker collects the frogspawn and lets all the jars hang out ("range") on his windowsills in his house. Left in the sun, they'll eventually turn to tadpoles.
He also collects them for school. The end of line 13 finally introduces one of the reasons that our speaker is such an avid collector of the stuff. He brings them to school to study, too.

The fattening dots burst into nimble-
Swimming tadpoles. Miss Walls would tell us how

"The fattening dots" are the clumps in the frogspawn (like the "specks," these are the start of the tadpoles).
Exposed to the sunlight (on the windowsills), the frogspawn turns into tiny tadpoles.
Miss Walls is probably the speaker's teacher, and she is using the frogspawn and tadpoles to teach a science lesson. It's probably titled "How a glob of gross muck turns into frogs," or something like that.
Notice here how line 15 ends in mid-sentence? That, Shmoopers, is what's known in the biz as enjambment. It's the poetic art of stopping mid-line for a reader to consider that thought, then carrying over into the next line to complete it. In this case, we are told that "Miss Walls would tell us how," which just reinforces her role as explainer-in-chief for her students. We wonder what she tells them in this specific instance (we're guessing it's a frog-related fact). Let's read on through the enjambment.

The daddy frog was called a bullfrog
And how he croaked and how the mammy frog
Laid hundreds of little eggs and this was

Looks like Miss Walls is definitely their teacher, and she's giving them a science lesson in frog reproduction.
The male frog is indeed a bullfrog, and bullfrogs have a super-low and loud croak.
The female frog lays hundreds of eggs in the slimy frogspawn, and that's how tadpoles eventually come to be.
So far this lesson seems straightforward, and the speaker, who is probably pretty young in this memory, is fairly interested, if not enthusiastic, about this whole frogspawn thing. He probably finds it en-gross-ing. Get it? Huh? Okay, nevermind…

Frogspawn. You could tell the weather by frogs too
For they were yellow in the sun and brown
In rain.

This is a little aside about the frogs, presumably learned in the science lesson from school, that they change color based on the weather.
It seems like the speaker was totally interested in this lesson, and was kind of a frog nerd.
So this was an exciting part of the year for him. From gathering the frogspawn from the flax dam, to watching the tadpoles hatch in the jam jars.
Check out line 21. It really stands out, doesn't it? It's by far the shortest line of the poem, which seems to indicate that it's catching our attention for a reason. What could it be? Head to "Form and Meter" for more on how this poem is put together.