684 Marvels of the Universe 
THE SKULL OF A TWO-HORNED NARWHAL. 
The Narwhal usually has only one horn, with the second only slightly developed. Here the rudimentary second horn 
is fully grown 
the mass becomes actuated by a common impulse to seek the light, and it moves towards it with a 
rolling motion. 
One day, at the end of October, I came across the stump of a large pine-tree. The interior was 
decayed, and from it was pouring a sheet of cream that flowed over the bark. Several square feet 
of the bark were thickly coated with it, and there was evidently more to follow. With a strong knife 
I cut out a large piece of bark, and placed it carefully in a tin box. On reaching home, I at once 
took the photograph shown on page 681, which is the natural size. Then I placed it again in the 
box and closed the lid tightly. The bark was so placed that it nowhere came into contact with 
the sides of the box, as I hoped by this treatment the plasmodium would be induced to stay on 
the bark. 
The tin-box had contained tobacco, and the manufacturers had perforated its sides with their 
initials. The light, of course, found access through these perforations, and this low organism 
enclosed within, that had no eyes or other apparent sense organs, knew thereby the way out. By 
some means a portion of the plasmodium stretched across the gap between the bark and the box, 
forming a bridge through or over which more could follow ; and, to my surprise, next morning I 
found that part of the mass had gathered on the exterior of the still tightly closed box. I then 
opened the box to expose the principal mass as well, and took the second photograph (page 682). 
The box was again closed, but ultimately the whole mass made its exit through the small holes, 
and consolidated itself into two cushions on the outside, and these invested themselves with a thin, 
purple-brown crust, as shown in the third photograph (page 683). The whole of the contents of 
these cushions—which are known as ethalia—then broke up into a fine, snuff-like powder of a 
dark purple-brown colour, among which ran a number of microscopic threads with knots of lime at 
intervals upon them. The powder was a vast assemblage—prebably millions of millions—of spores, 
such as originally produced the swarm-cells. The crust, in drying, contracted, so that it split across 
THE SKULL OF THE NARWHAL. 
Showing the development of the horn from the frontal bones of the head. and the indications of a second. 
