Manchester Memoirs, Vol. Ivii. (191 3), No. 11. 



3 



fungus in the tissues is shown in the figure. The sorus 

 of teleutospores (/) rests upon a definite mycelial cushion 

 {c\ which has evidently been formed by the occupation 

 of the intercellular spaces by larger masses of hyphae, 

 leading to the disorganisation of some of the cells of 

 the collenchyma. The hyphse extend inwards in the 

 intercellular spaces of the cortical parenchyma, making a 

 very definite attack on the starch sheath. Strands of 

 mycelium pass into the vascular bundle by way of the 



Text-fig. I. T. S. part of the petiole oi Althaea rosea, showing 

 young pustule witJi relations of mycelium to host 

 tissues. Description in Text. x 36. 



less resistant phloem rays {m.r.), and hyphae then ramify 

 among the tissues of the phloem (////.). Branches of the 

 mycelium extend to the parenchyma within the circle of 

 bundles. This distribution of mycelium suggests a definite 

 absorptive system of hyphae in relation to the individual 

 pustule. 



In the stem {Text-fig. 2) the distribution of the fungus 

 in the tissues is similar, except that on account of the 



