68 
As we have bad occasion to mention the greet resoor®‘® 
of nature in effecting her objects, so we may now noti*^ 
the wonderfnl economy she observes in making t" 0 ^ 
resources subservient to different purposes. The water tj ^ 
only serves as a fulcrum for muscular action, but for 
purposes of respiration and the perfection of the ova ; and 
each of these functions it is equally indispensable. * 
function of primary inporlance in all animals appears to 
the respiratory; if this be deranged in these creatures ^ 
soon see the strange condition into which they are thro'; ^ 
and the contrast it forms with the healthy state, in w o > ^ 
every function beautifully depends on the others. If an J* 
tinia be placed in deteriorated water, it endeavours to m® 
up in the quantity what it loses in the quality of the wat |j ^ 
It imbibes so much as to distend the body to an enorm 0 '^ 
extent; so much as to make it resemble an inflated bladdjy 
rather than the animal it is. The pressure of the wa 
behind forces the stomach out of the mouth, which toget 1 
with the white threads, hangs in transparent lobes over ^ 
sides of the animal. As the respiration appears to be carr'^ 
on chiefly by vibratory cilia, and these filaments and ^ 
stomach arc dollied with them, their exposure greatly assf*^ 
the process by enlarging the surface and exposing it to tn° 
water. The ova also suffer a considerable check in ttlL ^ 
developement, lienee many that liavo been kept in unfavo 
able positions on the shores have never increased, and ha'’ 1 ^ 
become transparent, it could be seen that the ova were ve -j 
imperfectly developed in any and in some not at all ; 
there they are and have been for two years and halt- ^ 
same in number, though different in appearance. 
always thrive best that are most exposed to the violence ^ 
the sea. When thus distended their muscular energy ■, 
always diminished and sometimes nearly destroyed ; a 
supply of water, however, soon redeems them to 1 
healthy state. of 
The manner in which the developement. and exclusi ^ 
the ova takes place is still an undecided question. 
however who has watched these creatures, can have 
to observe the fully formed animals expelled alive thf ’ 
the stomach ; nor can any one who has been in the l> a ’ ( j,e 
dissecting them have failed to notice the young animals * n ^ 
interseptal spaces, exterior both to the ovaries al!t ,^ e< - 
threads, supposed by some to be oviducts. Mr. 1 calc - ^ 
planation seems to be the best, as it fully accounts for a .^s 
positions in which the young have been found. He ^jf 
that when the ova are sufficiently matured, they b urs . [jte r' 
membranous envelope and “ become lodged in the 
septal spaces from these points they can travel W 
