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BOTANICAL NEWS. 91
flowers was blooming abundantly. I made a short excursion to the small town
of Santa Rosa de los Andes, at tliefoot of the Cordillera. There the lower hills
bristle with tall Cacti, usurping the place of all other vegetation, and in
many cases covered with a parasitic leafless Lorardhiis, with bright scarlet
flowers. We spent the month of August very agreeably at Coquimbo, and
there I made the acquaintance of the NolanacecB for the fii-st time ; Jlona
ccelestis covering the lower slopes of the hills, and two species of Sorema being
abundant on the lower gi'ound. There, also, I saw for the first time the Ari-
stolochia Chiliensis, the beautiful little Schizopetalon, Carica jiyriformis,
Llagunoa glandulosa, Schizanlhiis fimbriatus, two species of Caladenia, a
Trichopetalum, etc. We returned to Valparaiso in the beginning of September,
and liere we have been since. Thei-e is now a wonderful variety of plants in
flower on the hills and intersecting quenadas,— Tropceolum tricolorum, two
yellow Calceolarias, a yellow and a deep purple Oxalis, a scarlet Alonsoa,
several species of (Eiiothera, Plsathea ccerulea, Puga coarctata, a Veriena,
Adesmia salpiglossis, Argemone, Tupa, Schizanthus, Anemone, Polggala, etc.,
being specially plentiful. To-day we start for the south, there to remain for
the next six or eight months. Excuse the hurry with -which this letter lias
been written, and believe me, my dear Sir, most truly yours, Robeet O. Cunningham."
YII. Report on the Open Air Vegetation at the Royal Botanic
Garden. By Mr. M'Nab. VIII. Report on the Botanic Gardens of Natal.
By Mr. J. M Ken, Curator.
Thursday, February 11.— Cliarles Jenner, Esq., Vice-President, in the chair.
The following communications were read :— I. Experiments on Colour-Re-
action as a Specific Character in Lichens. By Dr. Lauder Lindsay. Tlie
author remarked that the colour-reactions of heheus, the efiects of certain
chemical re-agents applied to their thalhis or apotliecia, had recently acquired
considerable importance, in consequence of tlie strong assertions of Dr. Nv-
lander and the Rev. Mr. Leighton, as to the value of the reactions in question
in specific or botanical diagnosis. These observations had led the autlior to
make a special series of experiments, in order to test the accux'acy of the state-
ments, and the following are the general conclusions to which he has arrived :
1. The same specimen, in the hands of the same opei'ator, in its difierent parts,
at different times, frequently exhibits colour-reactions different at least in degree.
2. The same species, in the hands of tlie same operator, and, still more
so, in those of diSerent experimenters, in different specimens from the same or
different localities, differing in freshness of collection or age, occurring in
diffei'cnt varieties or forms, or in different conditions of growth (fertile or
sterile, hypertrophied or degenerated), frequently shows colour-reactions differ-
ing equally in kind and degree. 3. Colorific quality is determined by circum-
stances (not fully understood) connected with (a) locality of growth in relation
to climatic, geogi-aphical, topographical, geological, or other conditions. (6)
States of development, in relation to sterihty, hypertrophy, or degeneration of
the vegetable tissues proper. 4. Tliis inconstancy of colorific property leads
the arcliil manufacturer never to depend on laboratory testings in the purchase
of his " orchella weed," or in determining its commercial value ; for it not un-
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