628 The Siphonophores. [ September, 
female bell carries one egg, which will be described in the next 
article. Its growth and development will be found in the 
same place. The eggs are dropped in the water and there fertil- 
ized. Male and female bells ripen their products at different 
times. When the egg has left the animal, the sexual bell shrinks 
up on the stem and is finally absorbed or dropped; a scar on the 
stem alone tells of its former existence. 
The male bells have more elongated pedi- 
<> cels than the female, but in both cases the, 
K y sexual products are borne on the probos- 
cis between the ectoderm, or superficial 
layers, and the endoderm. They probably. 
originate from the intermediate layers, Or 
mesoderm (?). 
Agalma becomes sexually mature while 
yet retaining embryonic features. A young 
form of the most common species in the 
Mediterranean (Agalma sarsii) has been 
called another animal (Agalma clavatum). 
It is, however, only an immature form 
arrived at sexual maturity. I believe Wan- 
onia cara is the sexually mature young of 
the genus Agalmopsis. Nanomia was found 
hues at Newport and Nahant. 
A few theoretical questions suggest themselves after this frag- 
mentary account of the anatomy of Agalma. The first question 
which arises is, to what great groups in the animal kingdom is It 
allied? From the study of the anatomy naturalists were led o 
believe that Aga/ma was a free swimming hydroid. -This theory 
was simultaneously and independently brought out twenty years 
ago by several naturalists. The Siphonophoræ were regarded as 
nydroids which instead of being fastened to the bottom of the 
ocean, were detached or free swimming, and the point of attach- 
ment of the fixed form was supposed to be represented in a feat 
to support the animal in the water. Many bitter personalities, 
Fic. 6.—Male bell. 
_ happily now forgotten, were indulged in by those who claimed to 
have originated the theory, and it was,defended with great zeal 
by its advocates. Embryology teaches another answer to the 
question of what Aga/ma is, and it is my purpose to speak of 
that answer after a consideration of the development of the 
animal, 
