21 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



clean suckers at once and make a fresh start, growing the plants 

 in pits or houses by themselves away from the affected plants, 

 and destroying the latter as soon as they have fruited. I am of 

 opinion that whatever nostrum is applied strong enough to kill 

 white-scale on Pines, as in the case of vines infested with 

 Phylloxera vastatrix, will also prove fatal to the plants. In my 

 case, I had the affected plants immersed in lime-wash at a tem- 

 perature of 130°, hanging them up by the heels for six hours to 

 drain and dry before being potted up, but without effecting a cure. 

 Some weeks previous to dipping the plants in liquid-lime I had 

 them dusted over while damp with a mixture of fine new soot 

 and sulphur with a like absence of any good result. 



ON THE SPECIES AND VARIETIES OF TULIPA. 



By Mr. J. Gilbert Baker, F.R.S., Keeper of the Herbarium, Kew. 

 [Read May 5, 1396.] 



The genus Tulipa, unlike its near neighbours Lilium, Fritillaria, 

 and Erythronium, is entirly confined to the Old World, whilst 

 Calochortus is confined to the New World. The Tulips which 

 have been cultivated for a long time in gardens belong to a 

 limited number of species, but within the last generation a great 

 number of new species have been discovered, principally through 

 the explorations of the Russians in Central Asia. There are at 

 the present time not less than 100 specific names to be taken 

 into account, and I propose here to briefly enumerate the groups 

 into which the species are classified. 



The first separate group is that of the true Tulips from 

 Orithyia. Of the latter sub-genus eight species are now known, 

 and as the flowers are small and not brightly coloured these are 

 only worth cultivating as curiosities. They all come from Japan, 

 China, and Siberia, and differ from the true Tulips in having 

 the ovary narrowed into a distinct style, as in Gagea ; whilst tho 

 true Tulips have stigmas sessile on the ovary. 



The Tulips may be divided into two sections, according to 



