The Everglades is a watery plain covered with saw grass that's home to numerous species of plants and wildlife.
At one and a half million acres, it's too big to see it all today, but this tour will offer you a good sampling.
This is a good place to start because it's home to many of the plants and animals typically associated with the Everglades.
You'll see many exotic birds， and, of course, our world famous alligators.
Don't worry, there's a boardwalk that goes across the marsh, so you can look down at the animals in the water from a safe distance.
The boardwalk is high enough to give you a great view of the saw grass prairie.
From there we'll head to some other marshy and even jungle like areas that feature wonderful tropical plant life.
For those of you who'd like a closer view of the saw grass prairie, you might consider renting a canoe sometime during your visit here.
However, don't do this unless you have a very good sense of direction and can negotiate your way through tall grass.
You have the good fortune of being here in the winter—the best time of year to visit.
During the spring and summer, the mosquitoes will just about to eat you alive!
I'm glad you brought up the question of our investigations into the makeup of the Earth's interior.
In fact, since this is the topic of your reading assignment for next time, let me spend these last few minutes of class talking about it.
There were several important discoveries in the early part of this century that helped geologists develop a more accurate picture of the Earth's interior.
The first key discovery had to do with seismic waves.
Remember they are the vibrations caused by earthquakes.
Well, scientists found that they traveled thousands of miles through the Earth's interior.
This finding enabled geologists to study the inner parts of the Earth.
You see, these studies revealed that these vibrations were of two types: compression or P waves and shear or S waves.
And researchers found that P waves travel through both liquids and solids, while S waves travel only through solid matter.
In 1906, a British geologist discovered that P waves slowed down at a certain depth but kept traveling deeper.
On the other hand, S waves either disappeared or were reflected back, so he concluded that the depth marked the boundary between a solid mantle and a liquid core.
Three years later, another boundary was discovered that between the mantle and the Earth's crust.
There's still a lot to be learned about the Earth.
For instance, geologists know that the core is hot. Evidence of this is the molten lava that flows out of volcanoes. But we're still not sure what the source of the heat is.