PORSILD — OBSERVATIONS ON NARWHALS 
11 
The distal part of every protruding tusk, as well in the young as in 
the full-grown individuals, is white and polished. In the rare cases of 
two developed tusks, sometimes the right one is shorter, but its distal 
part is polished to the same distance from the point as the other. From 
the polished point towards the base, the spiral furrows always show a 
dense red-brown or greenish algal growth, heretofore not mentioned. 
According to an investigation kindly made by Prof. L. Kelderup Ros- 
eavinge at Copenhagen, this alga is a sterile species of Rhodochorton 
probably Rh. rothii very common along the shores of Greenland. 
Several diatoms not determined were also found by me. 
The tusks of a large number of old males are broken at various dis- 
tances from the point. Of 314 specimens seen at one time by the late 
Prof. H. Jungersen, 107 were broken. The cavity is opened by the 
breaking, and the blood-filled content gradually oozes away. The 
broken end with its spirals becomes worn, the algal growth on the outer 
surface disappears, and the sharp edges of the fracture, are smoothed 
and polished; often the algae also develop a short distance into the cavity. 
The strangest feature is, however, that not seldom a 'point of another 
smaller tusk is found thrust into the cavity and then broken off, a real 
‘‘tooth-filling.’’ The occurrence of this strange phenomenon is well 
known to the Eskimos of Greenland, who tell wonderful tales about 
it. They say an old male with a broken tusk entices a younger one to 
thrust its tusk into the cavity, whereupon by a jerk, it breaks the 
tusk of the younger narwhal. Robert Brown (Proc. Zool. Soc., Lon- 
don, 1868, p. 90) says; “They seem to fight with them; for it is rarely 
that an unbroken one is got, and occasionally one may be found with 
the point of another jammed into the broken place, where the tusk 
is young enough to be hollow or is broken near enough to the skull.” 
Of “filled” specimens I have seen four, two at Godhavn, the best 
of which is here figured (plate 1). Another pair was kindly shown to 
me by Mr. J. Krogh, chief factor of the colony of Jakobshavn. All 
specimens were sent to the Zoological Museum at Copenhagen. Among 
the specimens seen by Professor Jungersen one was remarkable, as the 
filling was broken in the cavity of the larger tusk, not reaching its outer 
end. Thus it could not be pulled out, but only taken out after sawing. 
A fight between narwhals has never been observed by the Eskimos 
of my acquaintance. They declare the narwhals to be peaceful and 
well-behaved animals. If fighting amongst males regularly takes place, 
one might expect to find their heads scarred and wounded, but neither 
I nor my Eskimo informers ever saw this. In one of the cases I have 
