84 Ecological Notes. 
years ago, Dr. Overton 1 , of Zurich, shewed that the development of 
anthocyanin in leaves was nearly always connected with a deficiency 
of starch and a corresponding increase of sugar (glucose); in other 
words, the anthocyanin, leaves are “sugar-leaves.” Now, we have 
already seen that of 16 species cf Arctic plants taken at random, 
all shewed marked sugar reaction. We therefore apparently have 
in the general occurrence of anthocyanin in Arctic plants another 
link in the peculiar chain of their general economy. With regard 
to the actual position of anthocyanin in this chain, Pick 2 was of 
opinion that the pigments in question facilitated the passage from 
the leaf of the products of assimilation, and in support of this view 
Wulff finds that the red cell-sap is sometimes confined to special 
layers of cells which may be carbohydrate-conducting in the petiole 
and stem. In the absence of mere exact knowledge of the chemical 
processes by which this facilitation is supposed to take place, it may 
however, be questioned whether the formation of the red or violet 
pigment is not primarily a direct result of the modified metabolic 
processes going on in the assimilating and conducting cells. An 
accumulation of pigment originally arising in this way may well be 
of use to the plant in enabling it to absorb more radiant energy, 
and thus to help out its rather feeble vital processes. This view of 
its direct utility is held by Kernel’ 3 and is also endorsed by Wulff in 
his present work. 
Research in British Ecology. 
Investigations of very difficult and fundamental problems in 
the ecology of plants usually raise more questions than they answer, 
but this is a natural occurrence in research on subjects of which 
our ignorance is so great, and only shews the necessity for active 
and determined work in all directions. As the periphery of our 
area of knowledge is widened, its points of contact with the vast 
fields which are still obscure increase in number, and this is a necessary 
feature of all progress. Dr. Wulff’s researches are an excellent 
example of the kind of work that has to be done, not only on Arctic 
plants, but on those of plant-communities nearer home. The 
ecology of the British Isles is a strangely neglected field of research. 
On the whole, no doubt, our flora closely resembles that of North- 
1 Beobacbtungen und Versuclie iiber das Auftreten von rotlien 
Zellsaft bei Pflanzen.—Jalirb. f. wiss Bot., 1899. 
* Bedeutung des roten Farbstoffs bei den Pkanerogamen— 
Bot. Centralblatt, 1883. 
3 Pflanzenleben, 1896, p. 379. 
