﻿On an abnormal cone in the Douglas Spruce, Pseudotsuga mucronata. 



B<t Francis E. Lloyd. 



(With Plate 327.) 



Wh 



had grown in a grove at Forest Grove, Oregon, the writer found 

 a tree about 40 years old in which the leader of the year before 

 had produced in its upper portion a cone which was abnormal 

 both in its position and structure. 



Normal cones are produced from lateral buds at the ends of 

 twigs in the middle and lower portions of the tree. During the 

 few days while pollination is in progress they stand upright. After 

 pollination, however, they exhibit a downward movement till the 

 position is entirely reversed and the cones hang down, in doing 

 which they have assumed the position characteristic of the 

 spruces, to which the Douglas Spruce is closely allied. 



The normal cones are from 7 to 10 cm. in length and when 

 mature and dry the scales spread to make a width of 4 to 4.5 cm. 

 The ovuliferous scales are orbicular in outline, and are concave 

 above. Each scale is subtended by a so-called bract, which is 

 nothing more or less than the leaf which subtends the scale, but 

 which differs from the ordinary foliage leaves in being expanded 

 laterally. The character of the lateral expansion is of great inter- 

 est,for we have here a structure which strongly suggests a stipular 

 affair. So far as the topography of the bract and the ontogenetic 

 series found in the female shoot offer evidence, it would seem that 

 we are justified in so regarding it At the base of the cone the 

 lateral expansions are quite small and at the base of the bract. In 

 ascending the cone the blade gets smaller gradually till it becomes 

 at the top a mere point on the tip of the now triangular scale-like 

 bracts which are quite primitive in character. That these expan- 

 sions are, strictly speaking, stipules may be objected to on the 

 ground that there is not developed therein any vascular tissue, 

 for it has been held that the development of such tissue is a 



(90) 



