pointed out, has never been found in numerous places where the 

 black rust came on later, or the two have appeared together in 

 September when the ^ops had begun to ripen and die a natural 

 death. This frequent appearance of the black, fall stage of the 

 rust in places where no trace has been found of the two stages 

 which should precede it, must, it seems to us, be explained in one of 

 the following ways : Either the earlier stages did occur, but were not 

 observed, th^se being quite scarce perhaps, or the spores came from 

 a distance and produced the black rust, or, finally, the rust is able 

 to skip over some of its stages as is the wheat rust. The first two 

 of these suppositions cannot, of course, be absolutely contradicted, 

 but, since cireful and repeated examinations made of our bed here 

 at the college during two summers failed to reveal any trace of the 

 rust before Sept. loth, we feel fully convinced that not a single par- 

 ticle of the spring or summer stage had developed. Furthermore, if 

 the fungus can and does pass through its full course of development 

 in all cases of its occurrence, that is if the spring and summer stages 

 always occur before the fall stage can develop, there would seem to 

 be no reason why they should not be abundant and common rather 

 than exceptional. There were certainly enough teleutospores pro- 

 duced in the fall of 1897 to infect every plant in the State the fol- 

 lowing spring, but since such infection did not take place and the 

 rust appeared in scarcely a single instance before the fall stage 

 came on in September, the conclusion seems reasonable that one or 

 more of the cases mentioned in connection with the wheat rust must 

 have occurred. In beds where the teleutospores were produced 

 in 1897, these spores, which evidently failed to infect the plants in 

 the spring of 1898, may have retained their vitality until late sum- 

 mer and then have produced the rust in the fall stage, accompanied 

 in some cases by a few belated uredospores. Another supposition 

 is that the fungus remained alive over winter in the plant tissue, not 

 producing spores again until September. This occurs in the wheat 

 rust and several others. Tne hollyhock rust, ( Paccinia Malvacea- 

 rum Mont.j affords an instructive example in this connection. 

 This rust produces only teleutospores. If an affected plant be 

 brought into the hot house in midwinter and forced into growth, the 

 rust will at once break out upon it, showing that the filaments of the 

 fungus were still alive in the rootstock, and in the small, half ever- 

 green leaves which are found in the hollyhock. The large fleshy root- 



