1886.] Himalayan Spruce-fir (Abies smithiana). 3 



about 1 m.m. X 0*76 m.m., but in a fully affected one these become 

 1'43 m.m. x 1"10 m.m. The needles now curve outwards with their 

 convexities towards the stem, and the cecidia are borne usually in two 

 more or less parallel rows on the upper curved surfaces (fig. 2). 



The length of a fully affected shoot varies considerably, from an 

 inch or two to 12 inches or more. In one specimen, a terminal affected 

 shoot measured 9 inches in length, whilst two lateral shoots, also affected 

 and springing from its base, measured 6 J and 5 inches respectively (fig. 1). 

 The measurements of another very fine specimen, gathered from a branch 

 near the summit of a young tree about 15 feet high, were as follows. 

 The small branch upon which the affected shoots occurred sprang im- 

 mediately from a main lateral branch. This branch contained 15 shoots 

 in all. Their lengths beginning from the base were as follows : — the 

 first 1 inch, the second 1|- inches, the third 2 inches, the fourth and fifth 3 

 inches, and the sixth 3|- inches. So far all the shoots were quite free of the 

 affection, but the seventh was affected and measured 5 inches, the eighth 

 unaffected 4J inches, the ninth affected 9 inches, the tenth unaffected Sc- 

 inches, the eleventh affected 8 inches, the twelfth unaffected 6 J inches, and 

 the fifteenth and last affected 12 inches. Thus the affected shoots were on 

 the whole considerably longer than the unaffected. I cannot explain the 

 curious phenomenon here displayed of alternate shoots only becoming 

 affected and with such regularity. The phenomenon becomes even 

 more striking when it is observed that not a single needle on an affected 

 shoot escapes invasion, whilst, on the contrary, no single needle on one 

 of the intervening unaffected shoots, nor any one on the main stem, even 

 in the internodes between affected shoots, is ever attacked in any degree. 

 To all outward appearance, the disease is confined absolutely to shoots 

 of the present season's growth and does not extend to the branch of which 

 it is an immediate shoot, and which was of the preceding season's 

 growth. 



As regards the general characters and appearance of the affec- 

 ted needles, they are, as already stated, considerably thickened and 

 curved (fig. 2). The distal end of the needle is densely studded 

 with spermagonia, which appear as minute dark points uniformly dis- 

 tributed all around it. Towards the middle half these become much 

 less numerous, and, as the base is approached, they are few and confined 

 to the inferior surface of the needle. The spermagonia are developed 

 considerably earlier than the secidia. The general appearance of the 

 secidia is illustrated in figs. 2 & 3. They are borne mainly on the upper 

 surface of the spine in two parallel rows. In rare cases, they burst 

 through the inferior surface, but such Eecidia are isolated and smaller 

 than those on the upper surface (fig. 2 a). While still unopened, the 



