So How Many "Ologies" Are There?

The best we can tell, there are at least 1869 different "ologies" that are listed among the various English language dictionaries of the world. A full list can be found here or some of the most common ones are shown here. You'll be amazed that people study some of the things they do (ichnology is an example). The root word itself, "ology" or "ologies", simply means a branch of knowledge or learning.