SI'EK.M()(;oXE.S 



The mycelium in the leaf is strictly localised, forming little 

 knotted masses (plectenchyni<i) just beneath the epidermal 

 cells of the affected spot; all the cells <»t' this mycelium are 

 uninucleate. Some of these hyphae turn upwards, remaining 

 densely crowded and more or less parallel to one another, and 

 enclose the flask-shaped cavity, at length converging to a point 

 above it and piercing the epidermis at that place. Then the 

 upper end- of these h\ pli.e diverge ami form a brush-like bundle 

 surrounding a narrow canal, or ostiole, which connects the 

 cavity with the external air (Fig. 2). Meanwhile other hyplue 



Fig. 2. J'. Caricis. Vertical section of spermo- 

 gonp, on leaf of Nettle, x 200. 



from the base have grown up within the flask, and made a 

 lining to its lower half; these hyphse are exceedingly delicate 

 and numerous, and each abstricts from its end, successively, 

 large numbers of the spermatia (Fig. 2), accompanied by a 

 (piantity of sugary mucilaginous matter which binds the 

 spermatia into a coherent mass. The mucilage soon swells by 

 imbibition of moisture, and the spermatia are forced out of the 

 flask, through the ostiole, and form an orange globule between, 

 and on the top of, the diverging hairs. Ultimately the mucilage 

 dries up, or is washed away by rain, and the spermatia are 

 dispersed. 



The spermatia are very small, thin-walled, oblong or roundish 

 cells, each containing a single relatively large nucleus, but 

 little cytoplasm and no reserve material. When placed in a 

 nutritive solution, they are capable of a kind of germination, 



