DISEASES OF PLANTS. 947 



A (l('t;iil('(| .-Kcuuiil is uivi 11 (iT llic (lilTci-ciiccs in iinnloiiiical features of this 

 \-;iricly of rice in so t;ir ;is coiiiiinrisdns rail !»' iiiadc lictwccu foi'iiKn' conrlitions 

 and those lliat prevail at tlic iircscnl linic It is liclicvcd that tlic loss of 

 rcsistaiiic to lirnsonc is a plii'iiDUUMioii which accoinpaiiied the exai^Kcratcd 

 variation in llie plant in recent yejirs and is due to the action of fertiiizei-s 

 rather than to climate and other features of environment. 



A nnnil)er of infection experiments were carried on witli a commonly recog- 

 nized s]ieci(>s of Piricularia and Ilehninthosporiiuii. 'I'he brown spots char- 

 acteristic of infection from tliese fun.iii are descrilx'd. 'i"he author concludes 

 as a result of his study that l'iri<iil(iriii (/risen. /'. (trii:ii\ Hrlmiiifhosititriuiii 

 iiri/Ki. and //. Iiircicinn are different names of tlie same s[)ecies for which the 

 name ririi-iihiria arir.tr is iireferred. 



In combat ill.:,' brusone sulpliat(> of copper may be used at the rate of one- 

 half jiart to Kill of water. Some browning of the leaves and jrlumes is produced, 

 but where this ti'catment is adopt^d or P.ordeaux mixture is used at the same 

 rate as cojiper sulphate, the total weight of the crop is not appreciably 

 diminished. 



A bacterial disease of cherry trees, R. AnERiioLo and W. Ruhland {Arh. K. 

 I'.iol. Aiixt. 1.(111(1 II. Forfitw., ') {mm). .\o. i;. pp. 2i)3-3J,(K />/. J, fifis. 12).— \n 

 continuation of previous studies (E. S. R., 17. p. 11()5), the authors give further 

 accounts of their investigations on a bacterial disease of cherry trees that 

 has becoiiH' ((iiite destructive in jiarts of Germany. 



HiiciUKs .spdiH/idsiix. the organism suspected as being the cause of this 

 disease, has been i'e]ieatedly isolated, and inoculation exi)eriments sliow that 

 there c.-iii be no doubt that it is actively parasitic. Other organisms, jiarticu- 

 Inrly various s])ecies of fungi, appear associated with this disease, but they are 

 considered as of secondary importance. 



.Vfter giving a technical description of B. spoiii/ioxKs, the authors describe 

 their inoculation experiments in considerable detail. In their experiments 

 they freijuently found other species of bacteria, one of which seems quite con- 

 stant, but is believed to be saiirophytic. This species seems to be undescribed, 

 and the name 11. iiritans is given it. 



In the ])re\ ions account of this disease attention was called to a somewhat 

 similar disease on apples and plums. Subsequent investigations of bacterial 

 dise.ases of jplnm, prune, and npple trees showed that, while the organisms 

 resemble those causing the cheri-y tree disease, the bacteria are not Identical. 

 i;xiierimeiits comparing B. s/ionf/iosiis with B. (uiniloroiKs. the cause of the 

 pear blight, showed tlieir nonidentity. 



The authors state that the bacteria causing the cherry tree di.sease are 

 undoubtedly conveyed from tree to tree by insects and possibly to some extent 

 by winds and I'aiii. In attempting to combat the disease all means possible 

 should be ado]ited to iirevent insect visits. All infected parts of the trees 

 should be cut otf and burned and the wounds disinfected. 



The pajier concludes with a description of the associated species, B. irri- 

 liiiis. which is called a common saprophytic accompaniment of B. spo??.cr/o.s-)/.s. 



.\ brief list of the literature relnting to bacterial diseases of fruit trees is 

 given. 



Takeall in wheat (Jour. Dept. A<.jr. Ho. Axst.. Ill (IDOd). No. 5, pp. 280- 

 283).— X description is given of a disease of wheat, due to Ophiobolus (jramini.t. 

 reported as being present in practically every wheat district of South Aus- 

 tralia, and in some instances diminishing the yield fully .30 per cent. 



There seems to be a difference in susceptibility of different varieties of wheat 

 to this fungus. There is very little knowledge regarding preventive measures 



