664 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



differ as to whether they will really be found to do so in the case of 

 perennials. The writer of this article quotes passages from the 

 writings of A. Jordan to show that this careful investigator was 

 perhaps too much inclined to doubt the correctness of facts which 

 interfered with his preconceived theories, and he considers that in 

 studying these geographical races it is possible to rely to a certain 

 extent on both Darwinism and Jordanism in order to find an explana- 

 tion for the fixity of some of their biological and the variability of 

 some of their morphological characters. — M. L. H. 



Ranunculaceae, Flower in. By Dr. S. Trapl {Beih. Bot. Cent. 



Bd. 28, pp. 247-281; 16 figs.). — The author describes and figures a 

 large number of transitional perigon parts, nectary-stamens, &c., in a 

 large number of genera of this order. He finds an extrao^rdinary 

 variability in the flower diagram. Even Ranunculus acris is sometimes 

 acyclic. 



He considers that the original type is Calycanthus, which is entirely 

 acyclic from the bracts to the carpels. This has changed into hemi- 

 cyclic and encyclic types, and along with this has gone a parallel 

 alteration from polycycly and polymery to oligocycly and oligomery. 



Thus in Anemone blanda and Adonis vernalis there are two whorls 

 of eight petals. 



In Aquilegia there is a constant number of five parts in the whorl, 

 but there are seYeral whorls of stamens. 



In some Brazilian Eanunculi there are only a few extra carpels, 

 which prevent the flower being a pentamerous encyclic one. 



The succession is as follows : Polymerous acycly, polymerous 

 hemicycly, oligomerous hemicycly, oligomer ous polycycly, and, 

 fmally, oligomerous oligocycly, tending to a flower with five sepals, 

 five petals, five stamens, and five carpels, with members in the whorls 

 alternating. 



Along with this goes a differentiation of sepals and petals. In 

 true Eanunculaceae, the latter are either petaloid or nectarial, whilst 

 in Anemoneae and Clematids there is not any differentiation. 



Thus the order belongs to a stage of evolution which other orders 

 have passed through. 



Several interesting sports are figured. — G. F. S. E. 



Rhizoctonia, The Morphologry and Parasitism of. By 



F. J. F. Shaw (Mem. Dep. Agr., India, iv. No. 6, Sept. 1912; figs.).— 

 Species of Rhizoctonia attack a large number of different hosts, and 

 often cause considerable loss. Several forms are studied and their 

 cultural and morphological peculiarities noted. He considers the form 

 on potato, for which he selects the name Rhizoctonia solani, identical 

 with that attacking jute, cotton, ground nut, and cow pea. He con- 

 siders the form of Rhizoctonia, identified by Eolfs (see Journal 

 E.H.S. 27, p. 1182, etc.) with Gorticium vagum as its spore-bearing 

 stage, to be different from the foregoing R. solani.— F. J. G. 



