DISEASES OK PLANTS. 145 



(lepartnuMit of \\\v rniversity College of North Wales, in wliicli :> |)lats of J acre eaeh 

 were sprayed witli copper sulphate solutions, 2, 8, and 4 per ecnt solutions heing 

 used. The amount of solution api)Hed was at the rate of 50 gal. |)er acre. The 

 applieations, while not entirely. satisfactory, destroyed aljout »W per cent of tht' weeds 

 without any permanent injury to the cereal crop over which it was sprayed. (;ras.s 

 and clover seedhngs growing in the grain were unaffected by the treatment, and in 

 one instance ap{)eared to have been improved by the application. While not 

 altogether favorable, the results are thought to liave more than repaid the expense 

 of the operation, and if this were persisted in for a nnud)er of years the weeds would 

 be ultimately eradicated. 



DISEASES OF PLANTS. 



Notes on the life history of certain Uredineae, M. A. Carleton {Al)f<. in 

 Science, d. .srr., 13 [1901), No. 3:20, pp. 249, 2.50). — Notes are given on some investi- 

 gations of rust fungi conducted by the author. In the case of UromijceH evpjiorhix it 

 was demonstrated that this rust is able to propagate itself constantly through the 

 germinating seed of its host and in this way becomes practically a pereuTiial sj)ecies. 

 A.S far as known this is the only demonstrated example of this method of j)ropaga- 

 tion among the rust fungi. Culture experiments with the common sunflower rus-t 

 showed that the Puccinia and yEcidiun^ found on the sunflower are stages of the 

 same species, and it is probable that all the species of Ilelianthus bear the same rust 

 and that they have no distinction of host forms. The author rejjorts having 

 succeeded in germinating the peculiar thick-walled, one-celled spores of J'nccinia 

 re.niu.'<. Theje spores are shown to be neither nredosjiores nor teleutospores, but pai- 

 take of the nature of both. They seem to be a distinct type of spore form and the 

 author proposes for such spores the name amphispores. Experiments by the author 

 have shown that ^■Ecidiinn liiliercidntnm is a perennial species in its i)erennial host 

 OtUirrlioe iiivolucnttn, producing sjiores al)]e to germinate during the coldest winter. 



A tabular revie^w of the Svredish cereal rusts, J. EnrKssoN [Ztsclir. J'ttanzen- 

 kraitk., JO (1900), No. 3-4, pp. 14^-146). — A review is given of investigations by the 

 author on the specialization of rust fungi, in which the hosts of the different form 

 species are indicated. Following the classification given by the author, it appears 

 that Puccinia gram'mis secalis occurs on rye, barley, Triticum rejiens, T. caniimm, T. 

 desertorum, Elynmn arenariua, and Broinua secaUitua; form (iveniv. on different species 

 of Avena, orchard grass, meadow foxtail, millet, Lnmarkia aurea, and Trlsetnm (ll.'<- 

 llcltophyUum; form tritici on wheat; form air»' on Aira civspHom; form <i(jroMh on 

 various species of Agrostis; and form pn:v on Poa spp. 'Puccinia phlei-praleih'ds \s 

 found on timothy and Fc^tuca elaiior. P. glamaram in different forms occurs on 

 wheat, rye, barley, Elymus arenarins, and Triticum repens. P. ilisjter.'ta is found only 

 on rye, and P. triticina upon wheat. P. hromina occurs on a nunil)er of sjiecies of 

 Bromus, /'. agrojiyrina upon Triticum repeni^, P. holciaa on IIo/chk lanata.s and //. 

 mollis. P. irLteti is found upon Trii^etum ftarescots, and J', simpler upon barley only. 

 P. coronifcra, form avenw, occurs on oats; form (dopecuri upon Alopecuru.'i spp., and 

 form fe.ftucir upon Fe^tuca clatior. P. coronata calainagrosfi-'^ attacks < '(dani<tgr<»^tiH spp., 

 an<l form agronli.'t is rejjorted on species of Agrostis. For many of these si)ecies the 

 iccidial host is unknown. 



Culture experiments with a rust fungi, H. Klkhaiin {.hdirh. Wistf. Bat. [I'ring- 

 sheim'], 34 {1900), No. 3, pp. 347-404; «/w. in Bot. Ztg.,2. Aht., 58 {1900), No. 9, pp. 130, 

 131) . — Culture experiments with a number of species of rust fungi are reported. A 

 number of species of Melampsora occurring upon willows were studied. Formerly 

 all these species were gronjjcd under M. .tidicia, but a number of forms are now 

 recognized. Four have their cn-oma stage on fjtrix decidna, one on BHick sjjp., one 

 on EuomjmuK eurapiea, and one on Orchix lulifn/ia, and other species of orchids. 



