The work of Dr. Odeen Ishmael, The Guyana Story, provides information about the early grants of land as "estates" from which many grantees would subdivide into lots for sale. .
Dr. Ishmael's essay No. 24 covered the districts and included a map.
From Ishmael's essay 36, regarding the Growth of Georgetown, I put together this little timeline of the establishment and growth of plantations:
Demerara Land Grant Timeline
1746 – Gravesande began granting land on Demerara River banks
1748 - 18 plantations have been established (wonder which ones these were?)
1759 - Map of plantations ( Caerte van de rivier Demerary van ouds Immenary : gelegen op Suyd Americaes Noordkust, op de Noorder Breedte van 6 gr. 40 min)
1763 - Majority of population are English setters, owning roughly 1/3 of the existing plantations
1770 - Dutch bank provides credit to sugar planters – plantations in Demerara expand from 93 to 130
1775 - Gravesande dies at Soesdyke plantation
Dr. Ishmael covered Berbice briefly only with the following all that was found:
Berbice Land Grant Timeline
1732 – Berbice Assoc & Dutch West India Company establish charter to grant lands to private individuals
1735 - 12 estates in the Assoc. but 93 new private plantations (both banks of Berbice River) and 20 on banks of Canje
1762 - Did not provide the number of existing plantations but did provide population as: 4,423 (346 whites, 244 Amerindians, 3,833 Africans)