Conifers Without Normal Whorls. 



67 



Mexican pinon trees from three to six feet tall were found which, 

 although thev had made normal growth up to four or five years 

 ago, had not developed whorls since that time. The group of 

 trees occurred on a gentle slope with southern aspect in Duncan 

 Canyon, about one-half mile north of Peterson's ranch and close 

 to the point where the road turns east. The soil is composed 

 of coarse particled conglomerate and porphyry. 



Fig. 1 . White Fir without normal whorls for the last thrt- e vears (left) ; Leaders of Mexican 

 Pinon showing development without normal whorls (right). 



Like the Norway spruce abroad, the needles were slightly 

 longer than on the trees in the same clump which were producing 

 normal whorls. On most of the eighteen trees the needles above 

 the whorls were produced in dense clusters with a bare space 

 between each year's growth, but on at least one of the trees this 

 bare space was wanting. In every case the leaves produced at 

 the beginning of the yeai's growth were much longer than at 

 the end of the year's growth, which readily served to distinguish 

 where the season's growth had stopped in the tree that had no 

 bare spaces. Needles gradually decreased in length from 1.3 



