In ornithology, check lists are still always arranged in what purports to be a “natural” order of species and genera. Such a system has inescapable weaknesses and the results are delusive and misleading. It is recommended that within the genus the species should, so far as possible, be allocated to numbered species-groups (reasons to be published by the reviser), that the specific names should be printed in alphabetical order, and that each should have suffixed to it the number of any species-group to which it belongs. The use of alphabetical order has come increasingly into favour in other branches of zoology.