34 



BACTERIA IN RELATION TO PLANT DISEASES. 



From a comparison of these two tables it appears that none of the varieties regarded as 

 very susceptible twenty five years ago have ceased to be susceptible, but rather, that some of 

 them have been discarded by certain growers on this account. On the contrary, some of 

 the varieties then regarded as very resistant continue to be very resistant, e. g., Robert 

 Steiger, single red; Baron van Tuyll, single rose; Grandeur a Merveille, single bluish white; 

 Marie, single dark blue. It also appears that some varieties then regarded as resistant are 

 now classed as very susceptible, e. g., Charles Dickens, single rose; La Grandess, single 

 white; Czar Peter, single light blue; Hermann, single yellow, and Mont Blanc, single white. 



Respecting these latter cases, we may assume (i) that they have changed in this par- 

 ticular during the last two decades, or (2) that they were susceptible from the start, but 

 had not at that time been subjected to rigorous tests calculated to bring to light their 

 inherent susceptibility. 



For the sake of those who may desire to see all the discrepancies, I append also my 

 entire list, premising that o means very resistant; + much subject; and intermediate or 

 no report. To find the varieties not marked by these growers the reader has only to consult 

 any good catalogue of Dutch bulbs. 



Table giving complete list of varieties mentioned by one or more of the three Dutch 

 hyacinth growers in 1906, as resistant or susceptible to the yellow disease: 



Single red : 

 Amy o 

 Etna o 

 Garibaldi + 

 Gertrude 00 

 Homerus 00 

 Incomparable + 

 King of the Reds + 

 Linnaeus + 

 Pelissier o + 

 Prima donna + 

 Queen Mary + 

 Robert Steiger 000 

 Roi des Beiges o 

 Von Schiller + 

 Vuurbaak + 



Single rose : 



Baron v. Tuyll o o 

 Beautv of Waltham+ 

 Carlyle+ 

 Charles Dickens-\--\-^ 

 Dr. Livingstone + 

 Maria Cornelia +0 

 Gertrude o 

 Gigantea o o 

 La joyeuse + 

 Lady Derby o 

 Moreno o o 

 Norma o 

 Princess Helene + 

 Rosea maxima o 

 Rosine o 

 Sophia Charlotte + 

 Sultan's Favorite + 

 Windhorst + 



Single white: 



Alba maxima + 

 Alba superbissima + 

 Albertine + 

 Augenis Christiana o 

 Baroness van Tuyll o o 

 Blanchard + 

 British Queen + 

 Crown Princess + + 

 Grand Vainqueur + 

 Grande Vedette + 



Jenny Lind + 



La belle Blanchisseuse O 



La Grandesse + + + 



La neige + + + 



La precoce + 



L' Innocence o + 



Madam van der Hoop + 



Mary Stuart + 



Mina + 



Mont Blanc + + 



Paix de l'Europe o 



Mr. Plimsoll o 



Queen of England + 



Snowball + + 



White Bird o 



Grandeur d Merveille 000 



La Franchise o o 



Lord Grey + 



Mammoth o 



Voltaire O 



Single light blue: 

 Blondin o 

 Captain Bovton + + 

 Clio +' 

 Czar Peter + + + 

 Enchantress + 

 Grand Lilas -j- + + 

 Grand Maitre 000 

 La Peyrouse 000 

 La Precieuse + 

 Leonidas + + 

 Lord Beaconsfield + 

 Lord Derby + + + 

 Lord Palmerston + + 

 Orandates+ + 

 Pieneman o 

 Prince de Taillerand + 

 Princess Mary of Cambridge -\- f 

 Queen of the Blues H \- 

 Regulus o o 

 Sehotel + + 

 Turquoise o 



Single dark blue: 

 Argus + + 

 Bleu mourant o 

 Baron van Tuyll o 



King of the Blues 000 



La nuit + 



Leopold II o 



Lord Mayo + 



Marie 000 



Baron von Humboldt + ^ 



General Havelock -f- + 



King of the Blacks + + 



Masterpiece + + 



Mimosa + + 



Pasteur + 



Sir Henry Barkley + + 



Uncle Tom + 



William I + + 



William III + 



Single violet, lilac, and mauve: 

 Distinction o 

 Lady Stanhope + 

 Laura + 



L'Honneur d'Overveen+ 

 Lilas enorme + 

 L'L ; nique + 

 Mauve Queen o 

 Sir Edwin Landseer + 

 Sir William Mansfield o 



Single yellow and orange: 

 Anna Carolina + 

 Bird of Paradise + + 

 City of Haarlem + 

 Ducde Malakoff + 

 Hermann + + + 

 Ida + + 



King of Holland + 

 King of the Yellows o o 

 La Citroniere + + 

 La Grande Jaune + 

 L'Or d Australie + + 

 Marchioness of Lome + 

 Obelisque o + 

 Yellow Hammer o o 



Double red: 



Eastanjebloem o 



Noble par merit e O 

 Princesse Louise + + 

 Princesse Royale o o 



