I can't seem to find an authoritative answer to this anywhere else online.
Basically, my school text-book says the antheridium (male organ) is located on the lower surface of the fern prothallus and the archegonium (female organ) is located on the upper surface of the fern prothallus.
Another (somewhat unreliable) book mentions that both the antheridum and archegonium are located on the "ventral side". With regard to plants, I'm not quite sure what "ventral" is...is it the side that's in contact with the soil/substratum (i.e- the "lower" surface)?
Besides, which source is right? Or are they both wrong?