> Does anyone out there know why the larger cell size was used in the first
> place?

A Biometrical Study of the Influence of Size of Brood Cell Upon the Size and
Variability of the Honeybee (Apis mellifera L.)
by Roy A. Grout, 1931

INTRODUCTION
http://www.beesource.com/pov/lusby/grout/intro.htm

"Baudoux (7) in Belgium was the first to conceive the idea of using a larger
size of cell by increasing the size of the cell base on the artificial
foundation given to the bees. Others who have worked along this line are
Pincot, according to Gillet-Croix (26), and Lovchinovskaya (39). The work of
the first two has not been of a very scientific nature but convincing to the
extent that manufacturing houses are selling foundation with enlarged cells
and claiming good results for the use of same."

REVIEW OF LITERATURE
http://www.beesource.com/pov/lusby/grout/review5.htm

"Baudoux (7), of Belgium, was the first to advocate the use of artificial
foundation with an enlarged cell base. In 1893, he reports that a Mr.
Fromont measured natural combs and found that the greater part had 825 cells
per square decimeter in comparison with certain sheets of artificial
foundation which had as high as 907 cells per square decimeter. Baudoux,
struck by the reduction in the size of bees from an old skep containing
combs having 912 cells per square decimeter, conceived the idea of raising
bees in enlarged cells. He accomplished this by means of stretching normal
foundation to the size he desired and had by 1896 sufficiently proved his
point in Belgium, that a manufacturing company began to place upon the
market artificial foundation having an enlarged cell base. It was Baudoux's
contention that the nurse bees, following a natural instinct, filled the
bottom of the larger cell more copiously with larval food, that this
resulted in a larger bee, He also intimated that the larger bee would
generate more body heat which would result in a greater quantity of brood."