380 



UKEDINEAE. 



formed, and in this condition the funuiis hil)ernates, to develop 

 further in the following spring. It is only in very dry cold 

 winters that the needles dry up and fall off; as a rule they 

 remain on the trees. About the beginning of May the spore- 

 cushions break through the epidermis and give off multicellular 

 teleutospores, which are as a rule branched. 

 Thence arise the four-celled promycelia, with 

 sterigmata, from which a single sporidium is 

 abjointed. 



Diseased needles remain green except in 

 areas inhabited by mycelium ; yet needle-cast 

 soon follows liberation of the fungus-spores. 

 Starch is laid up in large quantity in diseased 

 needles during the first summer, but is com- 

 pletely used up again by the mycelium for the 

 formation of the teleutospore-patches, Spruces 

 may suffer considerably from loss of foliage 

 induced by this fungus, yet the risks are by 

 no means so great as in the case of Cliryso- 

 onyjxi rhodoilendri where the whole existence of the plant is 

 endangered. 



Uredospores are unknown for this species and an Aecidium 

 stage has not as yet been discovered. Eeess has shown experi- 

 mentally that the teleutospores germinate directly on spruce 

 witliout intervention of an aecidial stage. 



Chr. piceae Bare. On needles of Picea morinda in India. 



Chr. empetri (Pers.) (Britain and U.S. America). Uredospores on 

 Eiapctrum 'nigrum. Caeoma empetri (Pers.) is the aecidial form. 



Chr. pirolae (D. C.) (Britain and U.S. America). Uredo- and teleuto- 

 spores on Pjirold. Aecidia unknown. 



Chr. albida Kiilui. On Ruhus fruticosus in Germany and U.S. America. 



Fio. ilZ.—ChrysoMyxa 

 abictis on Picca cwilsu. 

 The sori occupy the 

 middle portion of each 

 needle, which is in con- 

 sequence yellow, while 

 the apex and base are 

 still green, (v. Tubeuf 

 del.) 



Cronartium. 



Teleutospores unicellular and remaining attached togetlier 

 in tlie form of a long coiled process; they germinate i7i 

 aitti and give off sporidia. The masses of teleutospores arise 

 on the place formerly occupied by a uredospore-sorus. The 

 ovoid uredospoi'es are abjointed from short stalklets enclosed 

 in sori with a short peridium. Aecidia are developed on other 



