Rakhaldas Bandyopadhyay,
The Origin of the Bengali Script
(1919)
“ In the Gupta period, the addition of a new variety of the alphabet is now possible, owing to the discoveries of the remains of ancient Indian civilisation in the deserts of Central Asia. Fresh discoveries have also made it possible to trace the gradual displacement of the Eastern variety of the Northern alphabet by the Western one, in the 5th and 6th centuries A. D., and to determine the exact epoch of the final displacement. Finally, new materials have facilitated the determination of the type specimens of each variety, in each particular century, with a nearer approach to accuracy. ”
