6 4 



TEXT-BOOK OF FUNGI 



being situated at the base of the chain, as in Penicillium, 

 Cystopus, etc.; or the order of development may be 



FlG. 22. Melampsora pinitorqua, a fungus whose aecidiospores are 

 produced in chains, i, top of a young pine attacked by the aecidial form 

 of the fungus ; 2, three chains of aecidiospores in different stages of 

 development ; 3, an aspen leaf with pustules formed by the teleutospore 

 stage of the fungus ; 4, section through a pustule or sorus of teleutospores, 

 as yet covered by the epidermis of the leaf. Figs, i and 3, rather less than 

 nat. size ; the remainder mag. 



acropetal, the youngest conidium being situated at the apex 

 of the chain, as in Heterosporium^ Cladosporium, etc. 



