NOTES AND ABSTRACTS. 



921 



the house and street, under the trees. The general effect is also infinitely 

 better if the pruning be done gradually as the tree grows, instead of 

 waiting till one final day and then cutting off most of the branches, 

 leaving crippled, crooked trunks, surmounted by a pinched and straggling 

 top.— C. H. II. 



Tremacanthus Roberti. By Spencer Moore {Journ. Hot. 491, 

 pp. 33-4 and pi. 456; 2/1904).— Description of the only known species 

 of a new genus of Acanthacece from Sant' Anna da Chapada, Matto 

 Grosso. — G. S. B. 



Trichocaulon Pillansii. By N. E. Brown (Gard. Chron. No. 903, 

 April 10, 1904, p. 242). — A new species belonging to the same family as 

 the Stapelias. It is very seldom that any of the species belonging to this 

 genus are found in cultivation in Europe. " They are very difficult to 

 increase by cuttings, and, as they inhabit the very driest parts of South 

 Africa, under cultivation they usually get too much moisture and die." 

 This species very much resembles a Cactus in appearance. — G. S. S. 



Tulipa Batalini. By C. H. Wright {Hot. 3Ia<j. 7991).— Native of 

 Turkestan. Nat. ord. Liliacece ; tribe TuUpea* Flowers golden-yellow. 



G. II. 



Tupistra Clarkei. By W. B. H. {Bot. Mag. t 7957).— Native of 



Sikkim. Nat. ord. Liliacere ; tribe Aspidistrere. A robust herb with 

 creeping rhizome. Leaves oblong, acuminate ; flowers in spikes, 

 1^ inch diam., dull reddish-purple within, buff without, close to the 

 ground. — G. H. 



Uredineae and Ustilagineae of Essex. By I . J. Chittenden 

 (Essex Xaturalist, vol. xiii. part 6, 1904). — This communication contains 

 an enumeration of 86 species of rust and smuts hitherto found and recorded 

 for the county of Essex, with their hosts and localities. As these fungi 

 are parasitic on living plants, county lists are of considerable interest. 



m. a C. 



Uredineae, On Fertilisation, Alternation of Generations, and 

 General Cytology Of. By V. H. Blackman (Ann. Hot. xviii. July 

 1904, pp. 323-367 ; 4 plates;. — Phragmidium and Gymn/jsporangium 

 were investigated. The alternation of stages with single and paired 

 nuclei, as described by Sappin-Trouffy, was confirmed, as was also the 

 fact that it is in connection with the acidium that the binucleate stage 

 first appears. 



The author finds the two-nucleate stage to occur in special cells of the 

 young aecidium, which he terms fertile cells. These fertile cells become 

 binucleate, not through division of their original nuclei, but by the 

 migration of the nucleus of a neighbouring vegetative cell of the mycelium. 

 This process is regarded as a reduced form of fertilisation, the fertile cell 

 having the character of a female cell in that it is stimulated to further 

 development by the entrance of a nucleus from without. 



The cytological characters of the spermatia lead the author to conclude 

 that these are male cells which have become functionle-s. 



