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CHAPTER III. 



SPERMOGONIA AND THE SO-CALLED SPERMATIA. 



These bodies are produced by the mycelium, which arises 

 directly from the entrance of the germ-tube of a promy- 

 celial spore, or from a perennial mycelium permeating the 

 tissues of the host-plant. 



The hyphae which are destined to form a spermogonium 

 become interwoven into an inextricable network in the 

 subepidermal tissues of the host-plant. They pass for the 

 most part between the cells, and are found more frequently 

 septate where a spore-bed is about to be formed than when 

 they are encountered elsewhere in the tissues of the host- 

 plant. Their contents are watery and transparent. From 

 this tangled mesh, immediately beneath the epidermis, are 

 given off a great number of branches of much smaller 

 diameter, as a rule about 2 or 3//. The general direction 

 of these finer branches is towards the epidermis. They 

 incline towards a central point, however, and so come 

 together, forming a pyriform or subglobose body, the upper 

 part of which is covered only by the cuticle of the host- 

 plant. This body soon assumes a pyriform or flask-shaped 

 contour (Plate I. Fig. 3). The neck of the flask bursts through 

 the epidermis as a minute conical point, which can be seen to 

 consist of a vast number of straight hyphae, parallel to one 

 another in the main, but all sloping upwards, converging 



