[Phil27]

I am trying to learn schematics and this is probably a stupid question but I need to ask. I am looking at the schematic for a Philco 71. I was told if I wanted to understand schematics to try and trace the wiring on the radio and line it up with the schematic to get an understanding of how it all works. When I start looking at for example tube 44 and 36 on the schematic I see 6 points of contact going to each tube yet there are only 5 pins on each of these tubes.
I hope someone can provide a simple explanation because I’m trying to learn how to read these schematics but find it somewhat confusing. 
I have attempted to google my query as well as looked at some of the literature available and no luck.
I hope you all have some patience. Thanks.