The proper form of the word is _uacab_ or _vacab_, which the dictionary mentioned renders "cosa que esta en pie o enhiesta delante de otra." The change from the initial _v_ to _b_ is quite common, as may be seen by comparing the two letters in Pio Perez's _Diccionario de la Lengua Maya_, e.g._balak_, the revolution of a wheel, from _ualak_, to turn, to revolve.] [Footnote 2: The entries in the _Diccionario Maya-Espanol del Convento de Motul_, MS., are as follows:-- "_Chaac_: gigante, hombre de grande estatura.
"_Chaac_: fue un hombre asi grande que enseno la agricultura, al cual tuvieron despues por Dios de los panes, del agua, de los truenos y relampagos.

Y asi se dice, _hac chaac_, el rayo: _u lemba chaac_ el relampago; _u pec chaac_, el trueno," etc.] [Footnote 3: _Relacion, etc._, p.

255.] These four Chac or Bacabab were worshiped under the symbol of the cross, the four arms of which represented the four cardinal points.

Both in language and religious art, this was regarded as a tree.

In the Maya tongue it was called "the tree of bread," or "the tree of life."[1] The celebrated cross of Palenque is one of its representations, as I believe I was the first to point out, and has now been generally acknowledged to be correct.[2] There was another such cross, about eight feet high, in a temple on the island of Cozumel.