Manchester Memoirs, Vol. Ivii. {\^\^^, No. \\.. ii 



tube penetrates the epidermis between two epidermal 

 cells. Whilst this method of entry has been observed, I 

 have as frequently seen the germ tube directly enter an 

 epidermal cell as described by Rathay.-* 



The germ tube produces a slight swelling at the tip 

 and then enters by a fine neck, expanding within the cell 

 to form a large club-shaped infection vesicle. Whilst, in 

 form, this resembles the haustoria to be described later, it 

 seems better to give it a distinctive name on account of 

 its different behaviour and functions. PL \.,Fig. i shows 

 two sporidia lying on the epidermis seen in surface view 

 and sending their infection vesicles into the cell. For 

 comparison a germinating sporidium, the germ tube of 

 which has not penetrated the epidermis, is shown in PL i., 

 Fig. 2. The infection vesicle, which is often directed 

 towards the cell nucleus {PL J., Fig. 3), gives off hyphal 

 branches {PL /., Fig. 4). These either grow through the 

 cell wall into the neighbouring intercellular spaces, thus 

 starting the intercellular mycelium, or one of them may 

 enter an adjoining cell forming a second club-shaped body 

 like the primarj' infection vesicle. 



Sooner or later the intercellular life of the fungus is 

 commenced and the hyph?e advance rapidly into the 

 collenchyma and cortical parenchyma, sending short 

 straight or forked haustoria into every cell passed {PL /., 

 Figs. 5, 6). This rapid advance brings the mycelium very 

 quickly into relation to the starch sheath and vascular 

 bundle, a large number of cells being tapped in this way 

 by means of haustoria. The mycelium now aggregates 

 and begins to expand the intercellular spaces of the 

 collenchyma as already described {Text-Jig. 6), From this 



^ " Ueber das Eindringen der Sporidien-Keimschlauche der Pucchtia 

 malvacearuin in die Epidermiszellen der Althaea rosea.^^ Verh. K. K. Zool. 

 Bot. Ges. Wien, 1881. 



