t, it may eventually be possible, if past experience is a safe guide,
to show that the modified words form a natural phonetic group, that is,
that the "law" will have operated under certain definable limiting
conditions, e.g., that all words ending in a voiceless consonant (such
as _p_, _t_, _k_, _f_) were affected (e.g., _hoof_, _foot_, _look_,
_roof_), but that all words ending in the _oo_-vowel or in a voiced
consonant remained unaffected (e.g., _do_, _food_, _move_, _fool_).
Whatever the upshot, we may be reasonably certain that when the
"phonetic law" has run its course, the distribution of "long" and
"short" vowels in the old _oo_-words will not seem quite as erratic as
at the present transitional moment.[154] We learn, incidentally, the
fundamental fact that phonetic laws do not work with spontaneous
automatism, that they are simply a formula for a consummated drift that
sets in at a psychologically exposed point and gradually worms its way
through a gamut of phonetically analogous forms.

[Footnote 154: It is possible that other than purely phonetic factors
are also at work in the history of these vowels.]

It will be instructive to set down a table of form sequences, a kind of
gross history of the words _foot_, _feet_, _mouse_, _mice_ for the last
1500 years:[155]

[Footnote 155: The orthography is roughly phonetic. Pronounce all
accented vowels long except where otherwise indicated, unaccented vowels
short; give continental values to vowels, not present English ones.]

I. _fot_: _foti_; _mus_: _musi_ (West Germanic)
II. _fot_: _foeti_; _mus_: _muesi_
III. _fot_: _foete_; _mus_: _muese_
IV. _fot_: _foet_; _mus_: _mues_
V. _fot_: _fet_; _mus_: _mues_ (Anglo-Saxon)
VI. _fot_: _fet_; _mus_: _mis_(Chaucer)
VII. _fot_: _fet_; _mous_: _meis_
VIII. _fut_ (rhymes with _boot_): _fit_; _mous_: _meis_ (Shakespeare)
IX. _fut_: _fit_; _maus_: _mais_
X. _fut_ (rhymes with _put_): _fit_; _maus_: _mais_ (English of 1900)

It will not be necessary to list the phonetic laws that
gradually differentiated the modern German equivalents
of the original West Germanic forms from their
English cognates. The following table gives a rough
idea of the form sequences in German:[156]

[Footnote 156: After I. the numbers are not meant to correspond
chronologically to those of the English table. The orthography is again
roughly phonetic.]

I. _fot_: _foti_; _mus_: _musi_ (West Germanic)
II. _foss_:[157] _fo