VARIATION OF NITROGEN AND CARBOHYDRATE CONSTITUENTS DURING THE DEVELOPMENT OF HIMANTHALIA ELONGATA (L.) S. F. GRAY

¹ Botany Department, King's College, Newcastle upon Tyne, England

1. Monthly variations in chemical constituents have been followed throughout the development of Himanthalia elongata.

2. Nitrogen, laminarin, mannitol, alginic acid and fucoidin increase during the first year's growth of the vegetative button.

3. Associated with receptacle initiation, the carbohydrate and nitrogen reserve of the button is utilized and there is a synthesis of protein from the non-protein constituents.

4. The young receptacles build up a reserve of non-protein materials which are later utilized in protein synthesis during the formation of the gametes.

5. It was concluded that during the life history of Himanthalia elongata from germination to maturity and senescence, separate parts of the plant undergo their own ontogenetic changes which are correlated with changes in the chemical composition.