"Young man, you will be setting fire to the
schoolhouse." All winter long that faithful clock fire never failed,
and by the time I got to the schoolhouse the stove was usually
red-hot.

At the beginning of the long summer vacations I returned to the
Hickory Hill farm to earn the means in the harvest-fields to continue
my University course, walking all the way to save railroad fares. And
although I cradled four acres of wheat a day, I made the long, hard,
sweaty day's work still longer and harder by keeping up my study of
plants. At the noon hour I collected a large handful, put them in
water to keep them fresh, and after supper got to work on them and sat
up till after midnight, analyzing and classifying, thus leaving only
four hours for sleep; and by the end of the first year, after taking
up botany, I knew the principal flowering plants of the region.

I received my first lesson in botany from a student by the name of
Griswold, who is now County Judge of the County of Waukesha,
Wisconsin. In the University he was often laughed at on account of his
anxiety to instruct others, and his frequently saying with fine
emphasis, "Imparting instruction is my greatest enjoyment." One
memorable day in June, when I was standing on the stone steps of the
north dormitory, Mr. Griswold joined me and at once began to teach. He
reached up, plucked a flower from an overspreading branch of a locust
tree, and, handing it to me, said, "Muir, do you know what family this
tree belongs to?"

"No," I said, "I don't know anything about botany."

"Well, no matter," said he, "what is it like?"

"It's like a pea flower," I replied.

"That's right. You're right," he said, "it belongs to the Pea Family."

"But how can that be," I objected, "when the pea is a weak, clinging,
straggling herb, and the locust a big, thorny hardwood tree?"

"Yes, that is true," he replied, "as to the difference in size, but it
is also true that in all their essential characters they are alike,
and therefore they must belong to one and the same family. Just look
at the peculiar form of the locust flower; you see that the upper
petal, called the banner, is broad and erect, and so is the upper
petal of the pea flower; the two lower petals, called the wings, are
outspread and wing-shaped; so are those of the pea; and the two petals
below the wings are united on their edges, curve upward, and form what
is called the keel, and so you see are the corresponding petals o