What is the correct polarity for a bypass diode?

i am building a 60 watt solar panel and are going to install bypass diodes i have heard that you wire them in parallel but with reverse polarity this does not seem to make sense to me it seems like it makes sense to have them with the negative side of the diode to the negative side of the solar cells and vice versa what seems like every1 says is + side of diode to - side of cell it seem s that the cell would not bypass if in reverse polarity it would be just a open circuit even when cell is shaded if im not understanding correctly could someone explain this to me. i am not talking about blocking diodes