3. Hence it is that the etymologies of some names are not found, since certain things have received their name not according to the quality in which they originated, but according to man’s arbitrary choice. Etymologies are given in accordance with cause, as _reges_ from _regere_, that is, _recte agere_; or origin, as _homo_ because he is from the earth (_humus_); or from contraries, as _lutum_ (mud) from _lavare_—since mud is not clean—and _lucus_ (sacred grove), because being shady it has little light (_parum luceat_). 4. Certain words also were formed by derivation from other words; as _prudens_ from _prudentia_. Certain also from cries, as _graculus_ (jackdaw) from _garrulitas_. Certain also have sprung from a Greek origin, and have changed over into the Latin, as _silva_,[188] _domus_. [188] _Cf._ 17, 6, 5, where _silva_ (_xilva_) is derived from ξύλον (wood). 5. Other things have derived their names from the names of places, cities, or rivers. Many also are drawn from the languages of foreign peoples; whence their derivation is perceived with difficulty; for there are many barbarous words unknown to the Greeks and Latins. Chapter 32. On barbarism. 1. Barbarism is the uttering of a word with an error in a letter or in a quantity: a letter, as _floriet_, when _florebit_ is correct; a quantity, if the first syllable is prolonged instead of the middle one, as _latebrae_, _tenebrae_. And it is called barbarism from the barbarian peoples, since they were ignorant of the purity of Latin speech; for each nation becoming subject to the Romans, transmitted to Rome along with their wealth their faults, both of speech and of morals. Chapter 37. On tropes. 1. Tropes are so named by the grammarians from a Greek word which in Latin means _modi locutionum_. They are turned from their own meaning to a kindred meaning that is not their own. And it is very difficult to comment on the names of them all, but Donatus gave for practice a list of thirteen selected from the whole number. 2. Metaphor is the assumption of a transfer of meaning in some word, as when we say _segetes fluctuare_ (the grain-fields billow), _vites gemmare_, when we do not find any waves or gems in these things, but the words are transferred from the old application to a new one. These and other tropical forms of speech are veiled with figurative cloaks with reference to the things to be understood, with the view that they may exercise the intelligence of the reader, and may not be cheap because they are unadorned and easily apprehended.