Some of these words are no doubt exceptions. _Memoranda_ is preferable
when used collectively, but the English plural is better in such a phrase
as 'two different memorandums'. _Automata_, too, is sometimes collective;
and _lacuna_ always carries the suggestion of its classical meaning, which
makes half the meaning of the word. So again, when the classical form is a
scientific term, it is convenient and well to preserve its differentiation,
e.g. _formulae_ in science, or _foci_ and _indices_ in mathematics; but
such uses create exceptions, and these should be recognized as exceptions,
to a general rule that wherever there is choice then the English form is
to be preferred: we should, for instance, say _bandits_ and not _banditti_.


III. _ae_ and _oe_.

The use of _ae_ and _oe_ in English words of classical origin was a
pedantic innovation of the sixteenth century: in most words of common use
_ae_ and _oe_ have been replaced by the simple _e_, and we no longer write
_prævious_, _æternal_, _æra_, _æmulate_, _c[oe]lestial_, _[oe]conomy_, &c.
Since, however, those forms have a learned appearance, they are being now
restored in many words which had been freed from them; _medieval_ is
commonly written _mediæval_; _primæval_ and _co-æval_ are beginning to
make their appearance; _peony_ is commonly written _pæony_, and the forms
_sæcular_, _chimæra_, _hyæna_[1] and _præternatural_ have recently been
noted. As this is more than a mere change in orthography, being in fact a
part of the process of de-assimilation, members of our Society would do
well to avoid the use of the archaic forms in all words which have become
thoroughly English, and which are used without thought of their etymology.
The matter is not so simple with regard to words of Latin or Greek
derivation which are only understood by most people through their
etymology; and for these it may be well to keep their etymologically