I just spoke to a friend in the Adirondacks. In the northeast, a crispness hangs in the air and colors flash through the trees as fall approaches. Yet here, summer still blazes.

Los Angeles summers are luxurious, leisurely and long, so much so that we may not realize all that occurs during these months.

While we wilt and languish in the hot days, our mountain chaparral thrives and grows. Summer is a time for building, for putting on flesh and mass. Spring’s tender new leaves toughen and thicken. Flowers shift to ripe fruit. Holly-leaf cherries grow bulbous and red. Acorns take shape and lengthen out of their caps. Twigs turn to branches. The plants seem to bulk up, readying themselves for the turmoil of winter storms and the weight of new growth that comes with the first rains.

Summer is a time of growth for animals, too. Young quail take the shape and size of their parents. Coyote pup tracks show longer strides and bigger feet. Tadpoles morph into frogs.

A snake skin shed on a bare rock in the middle of a grassy meadow reminds me of all this animal growth. I pick it up and think about my own skin. Never in my own growth have I left behind a shell of my former self. Almost like a celebration, the snake releases its old, ill-fitting skin and makes room for the next stage of its life.

Snakes’ skin has evolved to suit the needs of a life without legs, arms or wings, a life of dragging its body along the ground through every sort of terrain. The skin must be rough enough to grip the ground for propulsion but also smooth enough to not be impeded by obstacles. Beyond that, a snake must also be tough and durable but remarkably flexible.

To attain this balance between smooth and rough, tough and flexible, the skin has an intricate system of scales. The scales are not separate pieces but rather one continuous piece of elaborately folded skin. Thicker portions of the skin form the outer scales, while the thinner portions are folded beneath them. Where the belly scales fall in a straight line, the scale folds are simple. On the back of the snake, where the scales are not linear, the folds are more complex.

This complicated structure allows for flexibility as well as distension, a necessary trait since snakes often consume prey that is wider than their own girth.

A snake’s skin shares some similarity with other vertebrates in that it is composed of layers. The innermost layer is soft, pliable and fibrous. The next layer possesses the pigments responsible for the snake’s color and patterns. Closer to the surface is the epidermis, which lies beneath a coat of keratin, the horny, thick outermost layer which protects the snake.

Keratin has almost no elasticity, and as the snake grows this keratin must slough off in a process known as ecdysis, or molting.

In humans or other mammals keratin forms hair or nails and the epidermis continually grows. Bits and pieces wear away without notice. A snake, however, loses its keratin layer in one smooth action.

Growth is the primary reason for ecdysis, but species, age, nutrition, temperature, humidity and reproductive status all regulate the frequency of molting. For instance, a young snake will shed its skin as often as once a month to keep up with its fast growth, while an adult that grows less quickly may only shed four times a year.

Unlike humans, who reach a determined size and stop growing in adulthood, snakes have indeterminate growth and therefore continue to shed their entire lives.

A snake begins to molt when an entirely new epidermal layer grows beneath the keratin. The top skin begins to look pale and less detailed as it pulls away from the body. The eyes become milky, and the snake experiences a period of poor eyesight.

When ready to lose the old layer, the snake opens it jaws to loosen the skin around the lips. By rubbing its head on nearby objects, its skin splits open and peels off the head. More rubbing allows the snake to slide out of its keratin layer, leaving a one-piece, inside-out suit of itself.

Seeing the snake skin on the rock, I bent down to pick it up and imagined the snake’s vulnerability growing from one stage to another. I then thought of all the children who also grow in summer.

What a huge transition the period from June to August is for them. They grow all summer, only to have to put on a new skin for the first day of school. And then it starts all over.

Meghan Walla-Murphy can be reached at the following e-mail: mwallamurphy@yahoo.com.