_All-fours._--In Macaulay's essay on Southey's edition of _The Pilgrim's
Progress_ (Longman & Co., p. 184.) occurs a curious use of this
expression:
"The types are often inconsistent with each other; and sometimes
the allegorical disguise is altogether thrown off.... It is not
easy to make a simile go on all-fours. But we believe that no
human ingenuity could produce such a centipede as a long allegory
in which the correspondence between the outward sign and the thing
signified should be exactly preserved. Certainly no writer ancient
or modern has achieved the adventure."
This meaning I cannot find in Bailey's _Dictionary_, and it has escaped
the curious vigilance of Blakie's compilers. The saying, however, is a
very old one. Sir Edward Coke employs it (_Coke upon Littleton_, lib. i.
c. 1. sect. 1. p. 3. _a._):
"But no simile holds in everything; according to the ancient
saying, _Nullum simile quatuor pedibus currit_."
There is a marginal reference here to 1 Hen. VII. 16.
Perhaps some of your philological correspondents can throw some light on
the origin of the phrase, or at least give me some other examples of its
use. Is the expression "To be on all-fours with" good English?