NOTES AND ABSTRACTS. 



171 



Worthy of mention are also ' Aida/ chamois suffused with terra- 

 cotta ; ' Brilliant/ scarlet ; ' Cupido/ rosy flesh ; ' Inka,' terra- 

 cotta and orange ; * Kermesinus magnus,' large carmine flowers with 

 magenta centres ; * Leda,' white ; ' Leucothea/ white with green 

 centre ; ' Limoneus/ citron with white centre ; ' Luna/ yellow ; 

 ' Mona/ dark red ; * Miranda/ heliotrope ; ' Nymphaea ' is like a 

 yellowish-white Water Lily ; ' Pelagia/ bright pink ; ' Venus/ pink. 



P. anguliger bears milk-white flowers, smaller than the hybrids. 

 P. phyllanthoides ' Deutsche Kaiserin ' is very floriferous. Its blooms 

 have the same colour as the rose * La France.' — 5. E. W. 



Picea Mariana, Layering of. By George D. Fuller {BoL Gaz. 

 June 1913, pp. 452-457; 6 figs,). — ^The Black Spruce forms ''layers" 

 freely in certain pioneer forest associations along the Saguenay River, 

 Quebec (Chicoutimi), which are found on granitic hills exposed to 

 the full sweep of the wind and where there is very little soil. 



Besides the Black Spruce, Pinus Banksiana, Paper Birch and Aspen 

 are abundant. The prostrate branches become covered with moss, 

 dead leaves, &c., and give out roots. Then young upright stems 

 often appeared, so that circular areas with a radius of 2-4 metres 

 became covered with vigorous young trees. Often large clumps of 

 small trees (six to twenty) could be referred to a single parent. This 

 layering was not noticed in P. Banksiana and seldom in Picea 

 canadensis, which rarely occurs in exposed rocky situations. 



G. F. S. E. 



Pigmentation and Assimilation in Plants. By A. von Richter 

 {Ber. d. deutsch. hot. Ges., Bd. 30, pp. 280-290). — ^The author has made 

 a thorough investigation of the process of assimilation in green, brown, 

 and red Algae at Naples. The Algae were placed in large glass cylinders 

 filled with sea-water of known carbon dioxide content ; plants of 

 the differently coloured Algae were exposed simultaneously, some to 

 pure sunhght and others to coloured fights (obtained by interposing 

 spectroscopically pure coloured screens), while in other series of ex- 

 periments the assimilation of green, brown, and red Algae in light of 

 varying intensities was determined. At the end of each experiment 

 the water was analysed for carbon dioxide, and the diminution of 

 this gas and the increase in oxygen were noted. From the results 

 the author concludes that the most important factor determining 

 the rate of assimilation in differently coloured Algae is not the colour 

 of the incident light, but its intensity ; that among marine Algae, 

 as among ordinary land plants, some species are " fight-loving " 

 and others " light- avoiding " — or, expressed in terms of Wiesener's 

 Lichtgenuss theory, some require a relatively high fight intensity 

 and others a relatively low intensity ; that the distribution of 

 marine Algae in vertical zones is related to these differences as to 

 Lichtgenuss in the different species ; that the pigments additional to 

 chlorophyfi in Brown Algae (phycophaein) , Red Algae (phycoerythrin). 



