THE HORTICULTURAL SOCIETY OF NEW YORK 



The observations made indicate clearly that it is difficult to 

 attribute blindness of tulips to any one cause. The experiments 

 with Rose Grisdelin and Cottage Maid prove that blind tulips 

 may bloom excellently in the following year : they are hence not 

 necessarily " run down " or " run out " bulbs. In fact all the 

 blind tulips noted above were grown from large selected bulbs 

 that could not be considered " run out." 



The possibility of fungous infection as a condition involved in 

 blindness has been considered. Various saprophytic fungi may 

 be found on the dead remnants of flowers and stems and on the 

 dead outer scales, of bulbs. These evidently are not directly in- 

 jurious to the plants. Examination of a large number of blind 

 tulips in 19 16 failed to reveal any traces of truly parasitic fungi. 

 In 191 7, however, a sclerotium- forming fungus was found, which 

 is clearly parasitic, at least in the outer scales. Its action and the 

 masses or crusts of sclerotia (compact, rounded or bead-like 

 masses of tissue of the fungus) are shown in No. i of Plate 37. 

 It appears that this fungus has not been previously reported in 

 America, but that it has been known to be destructive of bulbs in 

 Europe. 



The marked difference in performance of the two lots of 

 bulbs of Rose Grisdelin and Cottage Maid — those used in special 

 experiment and those planted in display beds — suggests that some 

 aspect of treatment such as drying out, storage, planting, etc., 

 may influence stages of growth and thus be concerned with the 

 development of blindness. But different varieties have per- 

 formed differently under quite identical conditions of treatment 

 and climate. Undoubtedly the critical stages in the development, 

 maturity and rest period of tulips are not only much influenced 

 by treatment, but are somewhat different for various varieties. 



2. Relation of Weight of Bulb to Blooming 



If a single large bulb of the tulip be planted in the autumn and 

 allowed to bloom in the following spring, and then dug up and 

 examined, it will be seen that the basal portion of the plant, with 

 rare exceptions, readily separates into from two to five or more 

 bulbs. These bulbs, which may be called sister bulbs, are of 



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