The Development of Tyloses and Secretion of Gum in·Heartwood Formation

Abstract

The origin of both the tyloses and the gumt which are commonly observed in the heartwood vessels of numerous species has been traced to the ray cells. Tyloses are developed in the heartwood of species in which the width of the aperture of the pits from vessels to ray cells exceeds approximately 10 Ii; in woods in which the width of the pit apertures is less than approximately 10 Ii gum is secreted into the heartwood vessels.