1886.] parasitic on Cedrus deodara. 225 



of these last mentioned cells is taken by smaller cells filled with starch 

 grains and a few sclerenchyma fibres. Several of these characters may 

 be seen illustrated in figs. 9 and 10, which, however, represent attacked 

 needles. 



Structure of Affected Needle. — The general outline of a transverse 

 section is considerably altered (fig. 9). The parenchyma cells, es- 

 pecially near the sscidia, are larger and rounder than usual, losing 

 their palisade like character and resembling spongy tissue (fig. 10). 

 The resin canals have entirely disappeared. The parenchymatous 

 tissue is invaded everywhere, bat especially in the neighbourhood 

 of the secidia, by mycelial filaments. These filaments are, however, 

 entirely arrested at the endodermal sheath. They are not convoluted 

 except at the bases of cecidia. They are best seen in the air-cavities 

 of the parenchymatous tissue and are of the usual characters, that is, 

 branched, septate, and filled with clear fluid or finely granular matter 

 (fig. 3). A few haustoria of the branched type penetrate the paren- 

 chyma cells (fig. 6) . The secidia are very superficial and measure about 

 0*177 m. m. in breadth by 0'166 m. m. in depth in transverse sections. 

 At their bases the mycelium is densely aggregated, pushing aside and 

 disorganising the parenchymatous and hypodermal cells (fig. 7.) The 

 hymenium is flat and regular, and the rows of secidiospores are given off 

 from pointed sterigmata (fig. 7.) There are no intercalary cells be- 

 tween successive spores, and each row consists of about six spores. 



The pseudoperidium is a very perishable structure, consisting of a 

 single layer of more or less irregular cells irregularly arranged together 

 and easily becoming detached from one another (fig. 5). In every 

 transverse section of a needle through an secidium from five to nine 

 spermagonia are involved. They are very minute, measuring about 0*081 

 m. m in breadth by 0*045 m. m. in depth, and very superficial, being for 

 the most part above the level of the epidermis. Their bases only are 

 insinuated between the epidermis cells, and the underlying hypodermal 

 cells are not displaced to any appreciable extent. The spermagonia are 

 generally flattened on their summits (fig. 7.) They appear to have a 

 special proneness to emerge on the margins of ^cidia encircling them, 

 for, in every transverse section of a needle passing through an cecidium, 

 a spermagonium (or part of one) may be seen at either side of the 

 secidium ("fig. 7.) 



The fficidiospores are spherical or oval with orange-yellow granular 

 contents (fig. 4.) The dry spores measure on an average 12*7 /it x 8'4/x; 

 but after moisture they swell considerably, attaining average dimensions 

 of 17"9 /;(. X 14-8 //,. The epispore is very thick and beset externally 

 with numerous prominent tubercles (fig. 4. c), giving, in optic section, a 



