OF THE HETER2ECI0US UREDINES. 369 



Australia, namely from New South Wales, communicated by 

 Mr. A. H. Sampson, and from Queensland, communicated by 

 Mr. James Sewell. Eecently Professor Custance has kindly 

 forwarded an extensive series of specimens, illustrating the same 

 fact, from South Australia. These specimens were sent in com- 

 pliance with a request made to these gentlemen for them. This 

 arose from the pointed manner in which Australian farmers, in 

 their letters to agricultural papers, complained of " rust " as 

 injuring their wheat-crops; not, as our English farmers do, of 

 mildew." The fungus, however, is identical in both countries 

 (Puccinia graminis) ; only in Australia the barberry, if it occurs 

 at all, does so to a very limited extent in gardens <fcc. Not only 

 are the uredospores less abundant in English specimens, but the 

 teleutospores are produced at a much earlier period in life of the 

 parasite. 



A second instance is afforded by Puccinia ruligo-vera (DC.) 

 in the eastern counties of England. Here we have an enor- 

 mous development of the uredospores as compared with that of 

 the teleutospores. The Mcidium occurs on certain of the Boragi- 

 nacece, but must be exceedingly rare in this district, for although 

 most careful search has been made for it annually for the past 

 ten years, I have never yet gathered a fresh specimen. This is 

 because the teleutospores are one of the earliest to germinate; 

 they do so, in fact, before the foliage of the aecidial host-plant is, 

 as a general rule, above ground, and in a condition to afford them 

 a nidus. The Mcidium is most frequently found upon Zgcopsis 

 arvensis, an annual which, up to the present time (May 7), has 

 not appeared above ground in the open, but since the end of 

 March the wheat-crop has been severely affected by the uredo- 

 spores of the fungus in question. 



A third instance is afforded by Puccinia obscura. In a recent 

 communication to the Linnean Society, I showed that this fungus 

 has its secidiospores upon Belli* perennis. Professor Farlow, on 

 learning this fact, at once wrote to me to the effect that the 

 Puccinia occurs with him in Massachusetts, but that the secidial 

 host-plant does not, and is only very rarely cultivated there in 

 gardens. He was kind enough to send me specimens of the 

 Puccinia, which were accompanied by a far more profuse develop- 

 ment of uredospores than 1 have ever seen associated with our 

 English specimens. 

 Since the above observations were made, I have received from 



LINN. JOUBN. — BOTANY, VOL. XXI. 2 D 



