In the ``typical tone language,'' tonal morphophonemics is of the same order of complexity as consonantal morphophonemics. The phonemic systems which must support these morphophonemic systems, however, are very different. The inventory of tones is much smaller, and commonly the contrasts range along one single dimension, pitch level. Consonantal systems are not merely larger, they are multidimensional. Morphophonemic rules may be thought of as joining certain points in the system. The possibilities in the consonantal system are very numerous, and only a small portion of them are actually used. Phonemes connected by a morphophonemic rule commonly show a good bit of phonetic similarity, possible because of the several dimensions of contrast in the system. Tonal morphophonemics, in a common case, can do nothing but either raise or lower the tone. The possibilities are few, and the total number of rules may be considerably greater. Often, therefore, there are a number of rules having the same effect, and commonly other sets of rules as well, having the opposite effect. Tonal morphophonemics is much more confusing to the beginning analyst than consonantal morphophonemics, even when the total number of rules is no greater.

The difficulty of analysis of any subsystem in the phonology is an inverse function of the size -- smaller systems are more troublesome -- for any given degree of morphophonemic complexity. This hypothesis will account for a large part of the difficulties of tonal analysis, as well as the fact that vowel systems are often more puzzling than consonantal systems. The statement of the system is a different matter. Smaller systems can of course be stated much more succinctly. A phonemic system can be stated without reference to morphophonemics, but it cannot always be found without morphophonemics. And the more complex the morphophonemic system is in relation to the phonemic base, the less easily a phonemic system will be analysed without close attention to the morphophonemics -- at least, the less satisfying will a phonemic statement be if it cannot be related through morphophonemic rules to grammatically meaningful structures.