protection, attraction, or aggression, there are still immense exceptions to the rule. This is particularly evident to anyone who has witnessed the glorious autumnal tints exhibited by the foliage of trees along the mountain slopes of the Rhine and Danube, and on the shores of the Canadian lakes.[1] These beautiful shades of red, violet, and yellow merely denote the proximate fall of the leaf and chemical processes incidental thereto. Many leaves—due to anthocyanin—are highly coloured on their under surfaces, a process probably which absorbs light and changes it into heat, and thus "in the ever green leaves of those plants in the depths of the forest which are natives of inclement regions, this advantage is obtained from the layer of anthocyanin developed on the lower leaf- surface, that every sunbeam, even in the cooler seasons, can be utilized to the utmost."[2]
We may probably have reached a stage in our investigations where suggestion may at least be valuable during a halt, and, where consideration may be given to facts, and attention to questions, which do not altogether quite advance new theories nor disprove older ones. Let us bring grist to the mill, even if others alone are capable of producing the meal; surely the naturalist can collate his facts, give his experience, and propound his views, without seeking a "patent" for every idea, or to be the parent of another theory. At the present time, among many students of biology there seems a desire to advocate what may be called a personal theory. Such workers will, with the greatest avidity, dissect and criticise the theories advanced by others. But their own theory is sacred, is, in fact, "totem." This feeling is almost a form of survival. According to Turner, one Samoan saw his god in the Eel, another in the Shark, another in the
- ↑ Brehm has described similar autumn beauties in the woodlands of Western Siberia. ('From North Pole to Equator,' p. 130.)
- ↑ Kerner and Oliver, 'Nat. Hist. Plants,' vol. i. p. 521. A case which seems to imply non-utility in vegetable markings is given by Prof. Thiselton-Dyer:—"There is a variety of the common oak with marbled foliage. A tree at Tortworth has borne acorns, and these are striped. At first sight it might seem odd that a variation in foliage and fruit should be correlated. But it is not so; the marbling is due to the partial suppression of chlorophyll in those portions of the ground-tissue which are exposed to light; and this tract of tissue is continuous in the leaves and the carpels" ('Nature,' vol. liv. p. 293).
