Papers from Dr. Th. Mortensen's Pacific Expedition 
: 1914—16,1) 
i 
Observations on protective adaptations and habits, 
mainly in marine animals. 
By 
Dr. Th. Mortensen. 
During the authors voyage in the Pacific regions from January 
1914 to March 1916 there was opportunity of making some inter- 
esting observations on protective habits and adaptations in some 
marine, and also in a few terrestrial, animals, which appear to be, 
Partly at least, hitherto unnoticed. It has been thought worth while 
publishing a short record of these observations. 
It may perhaps be found that the observations are remarkably 
few for a more than two years trip in the warmer regions of the 
Pacific, the richest zoological field in the world. There are several 
reasons for this, among which, however, I venture to think, not 
this that the author has not paid sufficient attention to the matter. 
In the first place, previous observers have recorded a good deal 
of conspicuous cases of protective coloration and habits, like f. i. 
the Sargasso fauna, the Zostera fauna, the fauna of sandy bottom, 
the pelagic fauna, or like Xenophora, Stenorhynchus, Phyllo- 
Pleryx etc. Such cases are fairly well known, and although they 
Cannot fail to rouse the admiration of anybody, who has the good 
fortune of seeing them — and nobody could fail observing numerous 
1 It is, for several reasons, which need not specified here, not planned 
to have the very large material, mainly of marine animals, collected 
during this Expedition, worked out so as to form a complete report of 
the scientific results of the voyage. It is only intended that papers based 
on material from the Expedition should appear under this main title. 
