Sense-Life and Sensibility 
intelligence. Striking as are many of the purposeful 
adaptations to be found in plant life, such an assumption 
cannot possibly be maintained. 
But it is necessary to abandon speculation and try 
to show how much of more recent work tends to ex- 
plain this difficult question of the purposeful working 
of plant protoplasm, 
There is first the extraordinary sensitiveness of both 
leaves, stems, and petioles to sunlight. According to 
Darwin, grass seedling will curve towards a source of 
light so faint that it is indistinguishable to a human eye. 
The careful experiments of Haberlandt have shown that 
not only the leaf blade but even its stalk are so affected 
by sunlight that both move and so arrange or display 
the green surface to the best advantage. One plant, 
Fittonia, has a tiny cell the shape of a biconvex lens 
placed at the top of prominent epidermis cells.’ 
That this acts like a lens scarcely admits of any 
doubt, and it will focus the light upon some particular 
layer inside the leaf. Should this focus be a sensitive 
protoplasm-surface which will react to light, then one 
can see that the leaf may, by the reactions of this pro- 
toplasm, shift its position until it is at the most desirable 
angle for illumination. 
These peculiar, lens-like cells have been compared to 
the primitive simple eyes found amongst many of the 
lower animals. 
That they do act like lenses scarcely admits of any 
doubt, for Haberlandt and others have made photo- 
graphs by means of these epidermis cells. Mr. Harold 
Wager exhibited at the Linnean Society, 19th Nov. 1908, 
several excellent photographs of flowers, landscapes, 
houses, and even of figures taken by means of these 
epidermis cells. Even autochrome plates (Lumiére’s) 
were used by him. When, as in some of Haberlandt’s 
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