7/3/79 TREE RINGS APPEAR TO BE EXTREMELY UNIFORM IN THICKNESS MORE SO THAN NORMAL TAXODIROID CONIFERS? THIS MAY BE A FUNCTION OF CONTROL BY ONSET OF ARCTIC NIGHT WHICH WOULD BE INVARIABLE IF NEITHER CLIMATE OR RAINFALL WERE LIMITING THEN ONLY SOURCE OF VARIATION MAY WOULD BE HEALTH OF INDIV TREE - INSECT ATTACK, FUNGAL DAMAGE IN A YEAR. WILL MEASURE RING WIDTHS X V VARIATION AGAINST MODERN TAXODIROID CONIFERS.