NOTES AND ABSTRACTS. 



619 



Damping-oS, Preliminary Tests of Disinfectants in Controlling it 

 in Nursery Soils. By Carl Hartley and T. C. Merrill {Phytopatho- 

 logy, iv. p. 89 ; April 1914). — Sulphuric acid, f oz. to the square foot 

 has given good results on soils in which pines were to be grown (the 

 damping-off being due to Pythium Debaryanum and to Fusarmm sp.), 

 but dicotyledonous weeds on the plots appear to be badly affected by 

 the acid. The suggestion is made that air-slaked lime should be 

 subsequently dusted on to the treated soil to neutralize the acid where 

 dicotyledons are to be grown subsequently. — F, J. C. 



Date Palm, "Fruiting Male" of. By H. Martin Leake {New 

 Phyt. vol. xiii. Nos. 1-2, pp. 69-70 ; 5 figs.). — The date palm is normally 

 dioecious, but cases have been recorded of the occurrence of so-called 

 " fruiting males " — that is, of male plants producing female flowers 

 or inflorescences. These observations have been made on the plant 

 when in fruit, but the writer gives details of the flowers themselves in a 

 case which he observed at the Government Botanic Gardens at Saharan- 

 pur, Northern India, where there is a date plantation in which different 

 varieties of date palms imported from various sources are cultivated. 

 Among these a plant was found which bore a whole series of inter- 

 mediate and hermaphrodite flowers, of which figures are given. Appa- 

 rently the change is not strictly the substitution of a monoecious 

 for a dioecious habit, as has been assumed in the previously 

 recorded cases. It appears that in these abnormal flowers the few 

 fruits that reach maturity are derived from the female flowers in 

 which the stamens have been completely aborted. The condition 

 of the hermaphrodite flowers, intermediate between the diclinous 

 flowers, is not confined to the stamens and pistil, for correlated 

 changes occur in the form of the perianth leaves ; in one case 

 figured the perianth segment opposite the single developed stamen 

 retains the character of the male flower, the two remaining segments 

 having a form approximating to that characteristic of the female 

 flower. In previous cases of " fruiting males " the plants were found 

 to bear clusters of small seedless dates, but the development of the 

 flowers here described was not traced further.— i^. C. 



Dendrobium speciosum and D. thyrsiflorum. By W. Dobberke 

 {Orchis, vol. viii. pp. 23-25 ; 2 plates). — Illustrations are given of 

 the shy-blooming Dendrobium speciosum and of D. thyrsiflorum in 

 flower.— S. E.W. 



Diseases of Trees in S. Appalachians. II. By A. H. Graves 

 {Phytopathology, iv. pp. 5, 63 ; February and April 1914 ; plate). — 

 Diseases of the Scrub Pine {Pinus virginiana) are dealt with, descriptive 

 notes on the following being given : Burl disease due to Cronartium 

 Quercus, which has as alternate host various species of Quercus ; 

 heart-rot due to Trametes Pini ; leaf-cast caused by Gallowaya Pini ; 

 and the rather rare attack of Coleosporium inconspicuum, which has 



