There are still persons in the Territory of Weihaiwei and its neighbourhood who call themselves _yin-yang hsien-shêng_, that is, professors of the principles of _yin_ and _yang_. Their functions are much the same as those of the _fêng-shui hsien-shêng_ or Masters in Geomancy.[202] As professional attendants at funerals their business is to see that all the arrangements are so carried out as to give every chance for the "vital essences" (_yang_) to assert themselves and to keep the dark and languid essences (_yin_) in their proper position of subordination. They select the propitious moment for starting the procession, for lowering the coffin into the grave and for every other act of importance in connection with the funeral; to them also is left--within limits--the selection of a favourable position for the grave.[203] The rules of _fêng-shui_ are complicated in the extreme; an error of a few feet in judging of the precisely favourable spot may completely shut off all the _yang_ influences and let in all the _yin_ influences with a rush, in which case--so it is supposed by believers--the family is doomed to misfortune and will probably before long become extinct. [Illustration: A PEDIGREE-SCROLL (CHIA P'U).] A southern aspect is supposed to be generally the most favourable for a graveyard, for the south is _yang_ whereas the north is _yin_; but other influences and conditions have to be taken into account as well--such as the contour of the neighbouring hills, the direction of valleys and streams, the proximity of human habitations, and many other things: so that a graveyard that has a northern aspect but possesses first-rate geomantic conditions in other respects is often far superior from the point of view of the professors of _yin-yang_ and _fêng-shui_ to a graveyard that has a southern aspect but happens to be overlooked by a badly-shaped hill or is near a river that has too many bends or flows the wrong way. Within the graveyard itself the good influences are not supposed to concentrate themselves solely and permanently on one spot; if that were so, the first people to die after the selection of the graveyard would obviously get all the best positions.