BY D. McALPINE. 463 



which, howeA'er, are accompanied by teleutospores. It is not to 

 \)e inferred on that account that the production of teleutospores 

 intermixed has any influence upon the size of the spores, for I 

 find that the uredospores of Paccinia pruni, Pers., are just as 

 large on a leaf producing them alone as when intermixed with 

 teleutosjDores. 



The late Dr. Ralph in a paper "On the Aecidium affecting the 

 Senecio vulgmn^, L., or Groundsel,"* stated that he was able to 

 trace by the use of strong carbolic acid the fine yellow sporular 

 matter into the covering of the seed, the seed itself and the hairs 

 of the pappus. It is interesting, as he points out, to find this in 

 the fruit and its appendages, since the hairy pappus surmounting 

 it would thus carry the fungus far and wide. I have found 

 yellow colouring matter in the hairs of the plant, but have been 

 unable to associate it with the fungus. 



The suggestion in the same paper that the source of I'ust in 

 cereals may be found in the Groundsel, taking the place of the 

 Barberr}^ bush in other countries, is rendered highly improbable 

 from the fact, apart from other considerations, that the teleuto- 

 spores proper to itself ha^e now been found on tlie Groundsel, 

 along with the aecidiospores. 



III. It has been shown by Dr. P. Dietelf in the case of an 

 allied fungus, Puccinia senecionis, Lib., that both kinds of spores 

 — aecidiospores and teleutospores — are produced from one and 

 the same mycelium, just as in Puccinia graminis, Pers., the 

 uredospores and teleutospores are similarh^ produced, so that 

 prol^abl}' here too aecidiospores and teleutospores have a common 

 origin. 



Classificatiox. 



This fungus belongs to the group Pucciniopsis, Schroet., having 

 aecidiospores and teleutospores on the same host-plant, and the 

 question naturally arises as to what species of Puccinia it belongs, 

 seeing that the Compositae have such a wide distribution, 



* Vict. Nat. viii. Xo. 2, IS (1890^. 

 t Zeitsch. f. Pflanzk. Vol. iii. Pt. 5, 258 {\H)^). 



