ZOOLOGY AND BOTANY^ MICROSCOPY, ETC. 423 



consisting of a colourless branched mycelium which penetrates the 

 bast and cambium to the outermost layer of wood ; on this mycelium are 

 the pycnidia, which burst through the bark, and contain the colourless 

 stylospores, 32-38 [x long, and about 11 jx broad. Shortly afterwards 

 the perithecia appear on the same spots. 



Nectria ditissima causes injury in oak and beech plantations from 

 fifteen to twenty years old, and on apple-trees in gardens. Phyto- 

 phthora Fagi has made its appearance on beech-trees. Fusicladium 

 ramulorum has appeared on the young shoots of several species of 

 willow and poplar, turning the leaves brown or black. The black 

 spots on the leaves and branches are covered with an olive-green 

 coating, which forms dendriform fissures, resembling those of F. 

 dendriticum. The conidia are bright greenish yellow, bilocular, and 

 of a peculiar form like that of the sole of a shoe, 18-20 fx long and 

 6-7 yu, broad. 



Puccinia graminis on Mahonia Aquifolium.* — C. B. Plowright 

 has determined that an sBcidium found on the berries of Mahonia 

 Aquifolium gives rise, when the spores are sown on the leaves of 

 wheat, to Puccinia graminis. This will account for the frequency of 

 the wheat mildew in districts where the berberry is unknown ; the 

 Mahonia being widely cultivated in gardens and shrubberies, and as 

 a cover for game. The same writer "f has also determined the dock 

 secidium, which is common on Bumex Eydrolapathum, ohtusifolius, 

 crispus, and conglomeratus, to be the eecidiospore of Puccinia Phragmitis. 

 On the other hand, the secidium of Bumex acetosa is not connected 

 with either Puccinia Phragmitis or magnusiana. 



Poly stigma rubrum.J— W. B. Grove gives some account oi Poly- 

 stigma ruhrum, Pers., based upon the recent investigations of A. B. 

 Frank § and C. Eisch||. It usually makes its appearance shortly before 

 midsummer on the leaves of Prunus domestica, P. spinosa, and P. 

 insititia. Its whole life-history is probably now known as Mr. Grove 

 shows. The only point left in doubt is the mode by which the 

 ascospores are conveyed from the ground to the young plum leaves. 



New Synchytrium.ir — Under the name Synchytrium pilificum, F. 

 Thomas describes a new species parasitic on Potentilla Tormentilla. 

 It produces tufts of hairs on the stems, flower-stalks, leaves, sepals, 

 and petals of the host, most frequently on the upper side of the leaves. 

 They proceed from a wart, 0-36-0 -39 mm. in diameter, and rising 

 0* 11-0 -27 mm. above the surface of the leaf; their number being 

 usually between 20 and 35. The base of the wart is of a yellowish 

 green or reddish violet colour. They do not seem to be very inju- 

 rious, as, even when the petals are attacked, the flowers produce 

 normal fruits. In the centre of each wart is a large brown cell, the 



* Proc. Roy. Soc, xxxvi. (1883) pp. 1-3. 



t Ibid., pp. 47-50. 



f Quart. Journ. Micr. Sci., xxiv. (1884) pp. 328-34. 



§ See this Journal, iii. (1883) p. (J85. 



II Ibid,, p. 247. 



^ Ber. Deutsch. Bot. Gesell., i. (1883) pp. 494-8. 



