Upon payment of the purchase price and the amount fixed as a proportionate contribution for endowment care, there may be included in the deed of conveyance or by separate instrument an agreement to use the income from such endowment care fund for the care, maintenance, and embellishment in accordance with the plan adopted, for the cemetery and its appurtenances to the proportionate extent the income received by the cemetery authority from the contribution will permit.
Ca. Health and Saf. Code § 8729