70 NOTE ON LEAF-FOLDING CATERPILLARS.
This water will frequently make the patient sick and vomit
whenever it meets with acids in the primae viae; but, if continued,
it destroys that acidity and agrees very well.
I observ'd that, by taking this water three or four mornings
successively, it turn'd the faeces black—a plain indication that
iron or steel is dissolv'd in this fluid; and, when it did not
operate by stool, it seldom fail'd by urine.
I cant help making one observation more, which I have long
made and establish'd in my mind as fact, and that is that all
mineral and medicinal waters are the most proper at the
beginning of a disease and rather hurtful in the same disease when
inveterate; [also] that they are equally improper in all continual
fevers and quotidians, inflammations of the lungs, hemorrhoids,
hemorrhages, spitting of blood, when an ulcer is form'd in the
lungs, and to women above three months gone with child.
Health and Strength is above all Gold and a sound
Body above infinite Treasure.—Eccl., 30th, 15.25
NOTE ON LEAF-FOLDING CATERPILLARS.
By ERNEST LINDER, B.Sc., and CHARLES KEY.
THE following observations were made in 1898, during the
course of Object Lesson Study when one of us was
working for the King's Scholarship. The experiments were
original and have been never published previously.
The larvae under observation [probably one of the Tortricidae,
Ed.] were found on a birch tree. In all stages of growth
they conceal themselves from sight by rolling up a leaf of the
tree on which they feed. The instinct appears to be a pro-
tective one.
The mechanism of the process of leaf rolling appears to be
directly connected with the silk spinning habits of the larva ;
no poison appears to be injected into the leaf substance, and
if the silk threads by which the edge of the leaf is secured be
cut, the leaf is seen to be uninjured.
If the larva be placed on a fresh leaf, it at once proceeds to
carry a thread across the surface of the leaf from one point to
another; a second thread is laid beside the first, and others
25 This quotation is not from the Book of Ecclesiastes, as might be thought, but from the
Apocryphal Book of Ecclesiasticas. The translation is very free and much more brief than
later and more literal versions.