458 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The tendency of green, white, and yellow to change to red or blue is 

 much stronger than the reverse. The floral colours are often correlated 

 with that of the stem and leaves, as in Sedum. The foliage of plants 

 with white flowers is as a rule paler than when the flowers are coloured. 

 The development of bright colours in autumn leaves presents a series of 

 colour changes which are in part parallel to those which occur in 

 flowers. 



The formation of pigments is affected by the chemical composition 

 of the soil, by altitude, or the intensity of light, by latitude, and by 

 absence or presence of moisture, as well as other ©ecological factors. 



Anchoring of Plantain-Seed. * — D. Griffiths discusses the process 

 of burying which is effected by a drying and contraction of the mucila- 

 ginous layers in the seeds of Plantago fastigiata. This plant grows 

 profusely in the deserts of southern Arizona. As in other species, the 

 seeds have a compact glossy or white coating which absorbs water, ex- 

 panding and becoming mucilaginous when an opportunity offers. After 

 a shower of rain, when the surface of the ground had dried, isolated 

 seeds were plentifully found, each sunken in a little pit in the ground, 

 the walls and bottom of which were made rigid by the hardened mucilage! 

 In the succeeding dry months it would become buried by the natural 

 abrasion of the soil. 



Burmanniaceae from Brazil.f — Eug. Warming describes two new 

 genera of saprophytes, Glaziocharis and Triscyphus, belonging to this 

 interesting little group of monocotyledons. They were collected by 

 P. Glaziou in the dark, damp, humus rich virgin forests of the State of 

 Eio Janeiro, especially in the region, Alto Macahe, from which Miers 

 described a number of saprophytic Burmanniaceae. The author also 

 describes a new species of Tliismia and offers remarks on the floral 

 biology of several species previously described by Miers, belonging to 

 the genera Dictyostegia and Apteria. 



Vegetation of the Mountainous Districts North of Lake Nyasa.i— 

 A. Engler describes the character of the vegetation of North Nyasaland as 

 shown by the collections made by a recent expedition. The mountains 

 reach nearly 3000 metres in height. The botanical features of the 

 following plant zones are successively described— the alluvial land, 

 the wet mountain forests, the steppe formations of the lowlands, the 

 xerophilous highland formation, the mountain steppes, the high woods, 

 the high-lying^ meadows, and the alpine vegetation. In spite of their 

 southern position there are numerous points of relationship with the 

 Abyssinian flora, while on the other hand several well marked South 

 African types occur. 



History and Development of Applied Botany.§ — A report of an 

 address by O. Warburg to the botanical section of the German " Natur- 

 forscher-Versammlung," in September 1901. 



* Bull. Torr. Bot. Club, xxix. (1902) pp. 164-9. 



t Oversigt k. Dauske Videnskab. Selsk. Forhandl., 1901, No. 6 (1902) pp. 173-88 

 (2 pis. and 6 figs.). 



% Sitzungsb. k. Preuss. Akad. Wiss. Berlin, xii. (1902) pp. 215-36. 



§ Ber. Deutsch. Bot. Ges., xix. (1902) Generalversammlungs-heft, pp. 153-83. 



