THE 



SCIENTIFIC PROCEEDINGS 



OF THE 



ROYAL DUBLIN SOCIETY. 



Vol. XIII. (N.S.), lo. 35. MAECH, 1913. 



ON THE ROTTING OF POTATO TUBEES BY A 

 NEW SPECIES OF PHYTOPHTHORA HAVING 

 A METHOD OF SEXUAL REPRODUCTION 

 HITHERTO UNDESCRIBED. 



BY 



GEORGE H. PETHYBRIDGE, Ph.D., B.Sc, 



ECONOMIC BOTANIST TO THE DEPARTMENT OP AGEICULTUKE AND TECHNICAL INSTRUCTION 



FOR IRELAND. 



(PLATES XLII.-XLIV.) 



i[A ufhors alone are responsible for all opinions expressed in their CommunlGatioiis.l 



DUBLIN : 



PUBLISHED BY THE EOYAL DUBLIN SOCIETY, 



LEINSTER HOUSE, DUBLIN. 



WILLIAMS AND NORGATE, 



14, HENRI ET'I'A STREET, CO VENT GARDEN, LONDON, W.C. 



1913. /r<^\an /fJS.VfJj^N. 



Price Ttvo Shillings and Sixpence. ( JUL 7 1913 



