796 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



The anthers of Rafflesia possess no fibrous cells in their wall such as 

 the majority of Phanerogams exhibit. The cytological facts associated 

 with the development of the pollen grains were followed in some detail. 

 The reduced number of chromosomes in this plant (R. Patma) was 

 found to be twelve. In most Dicotyledons two nuclear divisions take 

 place in the pollen-mother-cell before a cell division is accomplished, 

 but in the RafHesias a cell division at once follows the first nuclear 

 division of this cell. 



The generative cell of the pollen grain is at no time clearly cut 

 off from the vegetative cell. The surface of the pollen membrane is 

 perfectly smooth, without spines, sculpture, or definite germ-pores. 

 The tapetum of the anther does not break down until late in the life 

 of the anther. In this respect it differs notably from the tapeta of 

 most Angiosperms, but resembles that of Ipomoea examined by the 

 present abstractor. 



The gynaecium of Rafflesia exhibits no actual carpels and no 

 uniform ovarial cavity. 



In quite large flower-buds and even in open flowers the ovules are 

 still at a very early stage of development. They only complete their 

 development after pollination. The ovule possesses only a single 

 complete integument, whilst the outer integument is reduced to an 

 inconspicuous rudiment. 



The development of the embryo sac takes place in quite the normal 

 and usual manner. 



There is reason to believe that the flowers are insect-pollinated. 

 The development of the embryo was carefully followed, but exhibited 

 no remarkable features. The ripe seeds of R. Patma possess from 30 

 to 40 endosperm cells. The food-reserve in these, as well as in the 

 cells of the embryo itself, chiefly consists of oil. 



Quite a number of fruits of Rafflesia were collected by the authors. 



The seeds are only set free by the decay of the fruit. They are 

 distributed through the agency of animals, to the feet of which the 

 sticky mass of decayed fruit and seeds becomes attached. — R. B. 



Ramularia, Mycosphaerella, Nectria, Calonectria. By H. W. 



Wollenweber (Phytopathology, vol. iii. pp. 197-242, Aug. 1913 ; 

 plates). — This is a morphological study of fungi with cylindrical or 

 sickle-shaped conidia, including many parasitic forms. — F. J. C. 



Raspberry Horntail (Hartigia abdominalis) (U.S.A. St. Com. Hort., 

 Cat. vol. i. No. 12, Nov. 1912 ; 13 figs.). — This is a comparatively 

 new pest to come under notice. The adult insect belongs to 

 the Hymenoptera and the family Siricidae. The larvae destroy 

 young new growth by boring spirally around and down the canes, 

 causing them to die in a few days. — V. G. J. 



Red-Oak and Hard-Maple Crossties, Experiments in the Pre- 

 servative Treatment of. By Francis M. Bond (U.S.A. Dep. 



Agr., Forest Service, Bull. 126, May 26, 1913).— These were carried 



