How do I include a legend on this table for my lab report?

I handed in my lab report draft and I was told that all of my tables were missing legends, but I don't know how to include a legend on a table. I know how to do it on a graph like a line or bar graph, but not on a table. What does my TA mean when he tells me to put legends here? Thanks!

Mercy2014-12-01T20:15:55Z

I didn't know either.

I googled "legend for a lab report?"

https://www.google.ca/search?sourceid=navclient&aq=&oq=a+legend+for+a+lab+report%3f&ie=UTF-8&rlz=1T4GGNI_enCA530CA530&q=legend+in+a+lab+report+&gs_l=hp..0.0i22i30.0.0.0.11864...........0.znElakmxh8M

See the section called " TABLES"

http://www.bio.davidson.edu/molecular/Protocols/papers.html