Class attendance is very important to this course.  If you are going to miss a class session you may arrange to complete one of the following assignments.  Either requires advance approval from your instructor.

The Underground World of Caves
http://cdis.missouri.edu/studentinfo/coursedata/6252/6252.asp
The University of Missouri Center for Distance and Independent Study offers the Underground World of Caves Web site. The course includes an interactive step-by-step method of completing ten lessons that include everything from cave formation, cave life, cave ecology and conservation, and caves in the US, to general caving safety, moving through a cave, rappelling in caves, and ropes and belaying. Two online exams are included, as well as a photo gallery, additional links, and more.

The Mysterious Life of Caves
http://www.pbs.org/wgbh/nova/caves/
Another exceptional site from PBS online and Nova is entitled the Mysterious Life of Caves. Visitors can read an interview with a microbiologist about bacteria that live where nothing else can and from a journalist on caving 1,200 feet down a cave. The interactive section of the site includes a photographic journey through Lechuguilla, "one of the most strikingly decorated caves in the Americas" and a fascinating and very well done interactive Flash animation of how caves form. Anyone interested in caving, geology, or just nature in general will appreciate and enjoy this site.