Notes on Nectria Rubi. R. M. Nattrass 27

attenuated slightly towards one extremity. Average conidiameasure 37 x 5 /-'. In size and shape they agree with thoseof a species of Fusarium mentioned by Wormald* as occurringon diseased raspberry roots. This fungus has also been foundin association with "Crown Rot"; but it is not considered tohave any relation to N ectria Rubi, since it differs considerably,not only morphologically, but in cultural characteristics, fromthe conidial stage of that fungus. Further attention is beingdevoted to this Fusarium.

ADDENDUM.

Since the above notes were written a paper has come to handfrom Dr Wollenweber, "Pyrenomyceten-Studien, II" (Angew.Bot. VIII (1926), 168), in which some reference to Nectria Rubi ismade. In Phytopathology, III (1913), 2II and 224, Fig. IS,Plate XXII, Wollenweber transferred this fungus to the genusHypomyces because it produces chlamydospores, although notabundantly. It is also listed in that genus in this author's"Fusaria autographice delineata" (Ann. Myeolog. xv (1917),8);but in his 1926 paper, mentioned above, it is reinstated in thegenus Nectria; and Neetria mammoidea Phil. et Plow. var. RubiWeese and Cylindrocarpon janthothele Wr. are given as synonyms.Although it would appear from the statement on p. 169 of the1926 paper that Dr Wollenweber regards the fungus as a parasite(Wurzelsehiidiger) of raspberry, in a letter to the writer he admitsthat this has not yet been proved. Nevertheless, he points outthat it belongs to a group of related fungi which are injuriousto plants and probably forms no exception.

G.H.P.

THE PARASITISM OF PLOWRIGHTIA RIBESIAON THE CURRANTt.

By Isme A. Hoggan, M.Se. (Cantab.), M.S. (Wise.)

(With Plates IV-VII and 2 Text-figs.)

INTRODUCTION.

PWWRIGHTIA RIBESIA (Pers.) Sacco has long been known as afungus causing a disease of the currant, and its morphologyhas been worked out in detail by previous investigators. Littleconsideration, however, has been given to the pathologicalaspects of the disease, and the present paper deals with an in-

* Wormald, H. Journal of the South Eastern Agricultural College, No. 22(1923), 48r.

t This work was submitted as a thesis in partial fulfilment of the require­ments for the degree of M.Sc. at Cambridge University in 1925.