49 SEPIIDA. 
death is equally announced by a change of colors, which grow 
dull. 
The swimming of the Sepia is differently effected, according 
to the speed required. A moderate progression is equally easy 
forwards or backwards. When the animal moves forward, the 
body remains horizontal; the tentacles, united and extended in 
front, rest on the fourth pair of arms. The Sepia follows in this 
manner the course of the water, the resistance of which bends 
the extremities of the united arms. A moderate backward move- 
ment is effected in the same manner; but the tentacles are more 
elongated and their extremities are somewhat parted; the arms 
are raised to the line of the body. The undulations of the fins 
commence at the front or rear, according to the direction which 
the animal takes. This method of swimming, due entirely to the 
fins, is not slow, for the normal movement of the Sepia is easy, 
elegant and rapid; but an occasion of disquietude, as the sight 
of an enemy, or a noise, causes a much accelerated, jerky and 
retrograde movement. To effect this the animal spreads its arms 
and suddenly reunites them ; whilst the fins, reduced to inaction, 
are folded upon the ventral face of the body, the posterior 
extremity of one of them covering that of the other. 
This accelerated action is then due to the movements of the 
arms, which cause a series of extremely rapid progressions, in 
which, perhaps, the funnel assists by its discharges. It is erro- 
neous to regard the funnel, as some have done, as the principal 
or only swimming organ of the cephalopods. 
The deposition of the eggs occurs some days after fecunda- 
tion. I have been a witness to the deposition of three or four 
eggs, but I was not able to distinguish the method of the opera- 
tion. A female laid about one hundred eggs, about fifty in a 
corner of the aquarium, and fifty on the opposite side. These 
egos were enrolled by their peduncles around the long leaves of 
Zostera marina (xviii, 13,14). The larger part of the egos were 
laid in the night, for I remarked them,in the morning for the first 
time; they were ‘already black. 
When the Sepia is laying, she embraces the leaf of Zostera 
with her tentacles, and a few instants afterwards the egg is 
attached. The female removed herself but little from her eggs, 
but she appeared to me to be sick, exhausted; she died three 
days after having commenced oviposition, and only a few hours 
after having attached her last eggs. 
I found the o ovary filled with a considerable quantity of eggs 
in all stages of development; the most advanced were already 
furnished with a white and opaque covering, but none of them 
were black like those attached to the Zosteras. The black color, 
then, is acquired at the moment of deposition, and it is probably 
due to a secretion of the glands which surround the oviduct. 
