138 Bacteriologie. — Floristik etc 



&' 



grown in pure ether, which is held to be the source of carbon used 

 in the metabolism of the plant. Trelease, 



Blake, S. F., Two new Zexmenias. (Journ. Bot. LIII. N" 634. p. 

 306-307. Oct. 1915.) 



Zexmenia columbimia from Columbia und Z. leticafensis (vom 

 Guatemala are described. E. M. Jes.son. 



Bolus, F. and L., Key to the Flora of the CapePeninsula- 

 (Ann. Bolus Herb. I. 1. p. 22—36. 1014.) 



The above is an artificial ke}- for determining the Orders of the 

 group Spertnaphyta (to be followed in subsequent numbers of this 

 publication b}' koj^'S to the genera and species) of Cape peninsula 

 plants. E. M. Jesson. 



Brenchley, W. E., Mapping as an ecological instrument. 

 (Trans. Norfolk and Norwich Naturalists Soc. IX. p. 723—733. 

 1914.) 



With the development of ecological research the conception of 

 the use of the map has gradualh^ widened, until now it is regarded 

 as a graphical representation of facts from which other facts and 

 hypotheses can be deduced, and upon which theories established 

 on a firm basis can be built. 



A series of maps of an area may illustrate various ecological 

 factors, as for instance the ph3^sical features, the distribution of 

 the different types of Vegetation, the contour of the ground and the 

 variet}' of soils presents; in some cases two series of facts may be 

 combined on the same map — the physical features and the distri- 

 bution of Vegetation types being a very usual combination. Various 

 types of map are utilised in order to express each factor in the 

 most effective manner. The general field map, charted on a 

 small Scale, gives an idea of the main topographical and Vegetation 

 features. This is most conveniently worked out b}" chain surveying 

 or plane tabling. More detailed observations are supplied by the 

 mapping of small selected areas or grids on a larger scale, the 

 most u;3eful grids being those of 25 feet Square or less. The trans- 

 ect serves the same purpose as the grid, except that the area under 

 consideration is very long and narrow, being of any length and 

 frequently one decimetre in width. The quadrat is useful to map 

 very small areas in great detail, especially when individual plants 

 have to be recorded, the large scale of '^/-^ being often used. 



The various types of maps are illustrated from Charts made at 

 Erquy, Brittany, and Balkenry Point, Norfolk, and the 

 methods of working are described. W. E. Brenchley. 



Merrill, E. D., On the application of the generic Name 

 Naiiclea of Linnaeus. (Journ. Wash, Ac. Sc. V. p. 530 — 542. 

 Sept. 19. 1915.) 



The genus Nanclea is made to comprise the species generally 

 referred to SarcocepJinhis, and the new generic name Keoiiaiiclea 

 is proposed for species that current pass for Nauclea. The following 



