994 Marvels of the Untverse 
The chick is now lying curled up lengthwise in the egg, with its beak touching the shell- 
membrane where this forms the wall of the air-chamber already referred to, at the broad end of 
the egg. By the twentieth day a great and momentous change takes place. A little conical 
stony knob has been growing at the top of the beak. It is now ready for use, and is applied, 
first of all, to break through the inner shell-membrane, and so enable the lungs to get their first 
draught of air, which has been stored at the large end of the shell, and in the chamber between 
the shell and this membrane, to which we have already referred. Thereupon a great change 
takes place. The pulmonary circulation starts into being—to cease only with life itself—and the 
blood at once ceases to flow through the allantoic vessels which we have already remarked, 
spreading out in a membrane lying just under the shell, and drawing air through its pores. The 
lungs having begun to discharge their proper function, this temporary lung is no longer wanted. 
The egg-tooth is now used for the last time, and this to file through the walls of the shell. Once 
a hole is made the breach is speedily enlarged and the bird—is hatched. 
It has now only to get dry, and as this process goes on the down gradually opens out and the 
fluffy little mite, which we know as the ‘ chick,” has 
begun a career which the demand for “ spring-chickens ”’ 
may speedily end, or he may have entered upon a 
long and joyous existence in some delightful farmyard. 
DEY SET RS WiOikeM 
BY BERNARD C. WHITE. 
Now that England has ironclads to guard her shores, 
and now that piers, built on iron girders, and jetties 
composed of great boulders or masses of granite have 
taken the place of the old wooden quays, the fear 
of the Ship-worm has become a thing of the past. 
But it was not so long ago that the Ship-worm was 
one of the most dreaded scourges of maritime enter- 
Ratio ts cai, Fee prise. The cause of all the terrors was, as far as 
THE CHICK IN THE EGG appearance is concerned, a very harmless-looking 
STE ees ears oR een ete eT creature—just a worm: certainly of considerable 
isynows readystoybrealithetshellgand obtaingaix jength, but slender and pale and very soft to the 
for the inflation of its lungs. S : 
touch, with a curiously-shaped “head” and what 
looked like a double tail. The trouble lay, not in any dangerous quality of the creature itself ; 
but in its social habits, in the multitude of its brethren, and, chiefest of all, in its fatal propensity 
for tunnelling into wood. The Teredo (for such is the title by which the naturalist knows the 
Ship-worm) is doomed to die unless it can find a home for itself in some bit of water-logged 
timber ; and as a result, no fragment of wave-washed timber was secure from its attack, and 
when once a Teredo had found a home in the core of the wood, others would immediately 
claim a share in the newly-found domain, and what before might have been a sturdy baulk of 
timber would rapidly be turned into a worthless piece of sea-drift as rotten as tinder. The worst 
was that the havoc wrought would be indiscernible until the damage would be too far gone 
to be remedied and the apparently sound wood ready to crumble to the touch. In fact, the 
action of the Teredo on sea-weathered timber is very similar to that of the termite in its 
ravages of dry woodwork on land. 
If the ravages of the Teredo be on a very large scale the resulting damage may be very 
serious ; for instance, the carefully-built-up coast-line of Holland has on several occasions been 
threatened with destruction on this account, as the dykes have been found to be so badly 
