INVESTIGATIONS ON PARAGUAYAN BATRACHIANS. 
209 
black or blackish-brown with great white spots ; beneath light brown with 
dirty white spots. 
Two specimen from Villa Sana near Asuncion, collected in April 
1903. The length from snout to vent 72 and 37 mm. 
The structure of the skin (pl. XIII, fig. 3) is highly interesting. The 
very thin epidermis consists only in 4—5 rows of cells (ep), immediately 
below which lies a stratum of enormously enlarged glands ranged close 
to each other (g). Every gland consists in polygonal cells ( eth ) and enve¬ 
loped into a fine membrane, studded with chromatophors (ch). The glan- 
dulous portion is separated above from the epidermis by a pigment-row 
(ps) and below from the fibrous layer by a similar row (pi) ; it is fur¬ 
nished above with pores Co), opening on the epidermis. Below the glan- 
dulous part the fibrous layer of the corium with undulated (c is 1 ) and 
regularly (c s' 3 ) arranged fibres is visible ; below the latter running capil¬ 
lary bloodvessels (v). I believe that-the glands secerne a milky 
fluid, which hardens on the air and forms a chitinlike depo¬ 
sit on the back, as in Stereocyclops incrassatus Cope.* In fact shows 
the young specimen chitinlike scales, studded the whole surface of the 
back and flanks. 
Biological remarks. The stomach of the adult was quite stuffed out 
with termites, among which were 386 workers and 17 soldiers. The fact 
that this frog nourishes exclusively with termites, shows sufficiently, what 
important factor he is in the house-keeping of nature and also ^ives any 
explanation of its organisation. For this reason it is easily unterstood 
that the skin is so much glandulous and that the secret hardened on the 
air for covering the back as a shield against the attackes of the termites. 
It seems that this peculiar struetur of the skin is only a mean of defence, 
arisen through the influence of the mechanical irritation by the attackes 
of the termites and became later a full adaptation to the mode of life 
through natural selection. The peculiar structure of the skin is, 
I mean, nothing else than an answer to the mechanical in¬ 
fluence of the mandible of the termites. I believe that the ossi¬ 
fied cornea in Stereocyclops serves the same purpose. 
In truth these are opinions, which cannot be finally decided at the 
writing-table, because only through investigations made on the animal 
in its free life and natural surrounding, we. should be able to clear up 
these questions. 
* G. A. Boulenger, Catal. Batr. Sal., 1882, p. 159. 
Annales Musei Natìonalis Hungarici. IL 
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