80 Observations upon the Habits, Structure and (February, 
by the branchiopore. Thus in any case there would be great 
difficulty for the ova to get into the mouth cavity, and when once 
‘in they would be fully as liable to be drawn down through the 
pharynx into the stomach as to be expelled from the body. But 
it seems to me that it is not necessary to suppose any such diffi- 
cult and abnormal passage, as it appears possible to harmonize, in 
a natural manner, the opposing views of Kowalevsky with those 
of Quatrefages and Wm. Müller, for apparently the ova may pro- 
ceed from the mouth, while actually they make their exit from the 
branchiopore. When we consider the position of Amphioxus dur- 
ing feeding time, that is, when it comes to the surface of the sand, 
we find that it has formed for itself a sort of sand tube in which it 
lies, belly upwards, with its mouth orifice, or a small portion of its 
body exposed to view, as it was when Kowalevsky saw the ova 
- issue. Now at every contraction of the abdominal walls there will 
be left a space between the body and sand, extending from the bran- 
chiopore to the mouth, or near it, through which the water ex- 
pelled from the branchium may pass to and mingle with the water 
above the sand. And if at this time the ova are extruded from 
the pore along with the water, they will naturally rise to the sur- 
face of the sand, pass along by the mouth tentacles, appearing to 
any but the most careful observation to come from between them, 
and so into the medium where they float about until transformed _ 
into young Amphioxi. If this is the true method of procedure, 
as it is the most simple and natural, it will account, as no other 
method will, for the little bunches of fifteen or twenty which 
Kowalevsky saw emerge into the water. For in passing from the 
pore out against the sand it would be very easy for some of the 
= ova to become lodged against the sides of the tube until a num- 
ber of them accumulating together would form an obstacle of 
sufficient importance to be forced out by the outflowing water, 
and sent along by the tentacles, when they would be seen rising 
in the water as if just escaped from the mouth cavity. 
The Urinary System—The earlier anatomists who examined | 
Amphioxus were unable to discover any organ, or series of organs, 
which could be considered as acting as specialized excretory ves- 
sels for the urinary products, and for quite a time it was a matter 
= of considerable speculation as to the method by which these pro- 
_ ducts, if any were formed, were eliminated from the body. Very 
Soon, however, certain isolated, ductless, glandular patches were _ 
fo 
