PROTOMYCES. 



139 



distributing itself through the intercellular spaces, stimulates the 

 parenchyma-cells of the host to growth and cell-division. The 



Fig. 45. — Trotomyces macrosporus on leaf-stalk of Aegopodium Podagraria. 

 A, Mycelium and sporangium in the tissue xinder the epidermis. S, Sporangia 

 in stages of development, (v. Tubeuf del.) 



latter is a secondary process and consists (see Fig. 9) in the 

 formation of exceedingly delicate membranes inside the original 



Fig. 46. — Protomyces macrosporus. Section of petiole of Aegopodium witk two 

 swellings containing spores. Secondary cell-walls have been formed, and a 

 collenchyma region lies between the two swellings, (v. Tubeuf del.) 



cells of the parenchyma, so that they become divided into 

 younger cells rich in protoplasm and each showing a distinct 



