Why do procaryotic endospores get their own entry rather than being classified as a type of spore?  What is it about the definition of "spore" that the bacterial kind doesn't meet?  Their sporulation and germination processes and triggering conditions are analogous to those of diploid eukaryotes, and the asymmetric fission leading to formation of an endospore is similarly analogous to that of the asymmetric division producing eucaryotic spores.  I suspect a cladistic bias leading to classification on the basis of evolutionary origin rather than objective details of structure & function.