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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



sionally found on the canes, bufc the author beheves it to be merely a 

 saprophyte following the death of the canes caused by Leptosphaeria. 



Rose. — The production on the leaves of plants in houses of reddish 

 or purplish spots, later becoming brown with a purple border, was 

 found to be due to Mycosphaerella rosigena. It is not often a serious 

 disease. Mildew, Sphaerotheca pannosa, was found to produce 

 perithecia on both surfaces of the leaves of roses. 



Snowherry (Symphoricarpus racemosus) had its leaves and berries 

 much disfigured by the attack of a species of Gloeosporium, but the 

 growth of the bushes was but little affected. 



Sweet Pea. — Mildew {Erysiphe sp.) is reported on the sweet pea, 

 but no perithecia could be discovered. 



Vinca major variegata was attacked near the surface of the soil by 

 a species of Phoma, and the death of the shorts followed. — F. J. C. 



Plant Louse Notes. By 0. P. Gillette (Jour. Econ. Entom. 

 vol. 2, pt. 6, pp. 385-388, December 1910). — Notes on several species of 

 Aphididae with figures of antennae, &c. — F. J. C. 



Platyceriums. By H. Poisson {Rev. Hort. October 1, 1910, 

 pp. 458-60, and November 16, 1910; p. 530; one illustration).— An 

 interesting article on this curious genus of ferns, with names and 

 descriptions of fifteen different species : P. aethiopicum, P. alcicorne, 

 P. andinum, P. angolense, P. biforme, P. Ellisii, P. sumhawensi, 

 P. grande, P. Veitchii, P. Wallichii, P. Wandae, P. Willinchii, P. 

 madagascarense, P. Vassei, and P. Wilhelminae Reginae.—C. T. D. 



Pleiocarpa mutica (Bot. Mag. tab. 8343). — Nat. ord. Apocynaceae ; 

 tribe Plumerioideae. West Africa. Shrub 5 ft. high; leaves 3-6 inches 

 long; flowers in axillary, many-flowered, globose clusters; corolla pure 

 white, f inch across the limb. — G.H. 



Pollination, Studies for the Students of. By 0. H. Lewis 

 (Better Fruit, May 1911, pp. 79-85). — The emasculation of the flowers 

 must be done before the blossoms open. The blossoms should be care- 

 fully covered with paper bags until fecundation has taken place. Pollen 

 can be obtained by picking the twigs a little early and placing them 

 in fruit jars in a warm place. The anthers can soon after be gathered 

 and placed in a dish in a warm room, and after ripening the pollen can 

 be collected. A little camel's hair brush is as good as anything to use 

 in transferring the pollen. Very little pollen of either the apple or the 

 pear is transferred by air currents. The chief agent in pollina- 

 tion work is the bee, which is attracted by the bright coloured petals, if 

 these are removed few bees are attracted to the tree. Thus on one tree 

 the petals were removed from 1,500 blossoms, but only five apples set, 

 very few bees visited the tree. The aim has been to find the cause of 

 sterility. Eighty-seven varieties of apples were tested to ascertain which 

 were self-fertile and which self-sterile ; of these fifty-seven proved ster- 

 ile, including * King of Tompkins County, ' ' Gravenstein, ' * Dutch Mig- 

 nonne, ' 'Twenty Ounce,' and 'Wealthy ' ; fifteen varieties showed 



