9 
SEPIID®. 43 
The coloration of the eggs has not escaped the observation of 
Aristotle, but the explanation which he gives is more than 
doubtful. The very opaque and very dark skin of the excluded 
ego, later becomes thinner and nearly translucent. At the last 
period of development, if the skin is torn away and the viteline 
sack detached, one can introduce to the world, as I have often 
done, the young Sepia. It swims immediately, and changes 
color with the greatest facility. 
The coloration of the Sepias several centimetres in length is 
more variable than that of the adults. The zebra-like black 
bands are not seen, but the general tint changes instantly from 
gray to wine-brown, to violet, to green. The young Sepias sink 
into the sand, only showing a part of the back and the head ; 
they swim like the adults, but ascend and descend more fre- 
quently. 
The eye of the Sepia has a very strange appearance ; the dark 
pupil representing exactly a w. It is furnished with an upper 
lid, colored by chromatophores, and a narrower, whitish under 
lid; there is also a very distinct palpebral sinus. 
The sea-water destined for respiration enters the cephalic 
extremity of the branchial sack, and leaves by the siphon. The 
alternate movements of the openings of the sack and siphon can 
be readily seen. 
The branchial sack in a number of adult Sepias was dilated 
from seventy to seventy-two times a minute, but in the young, 
about an inch long, the inspirations reached 140 in a minute. 
This result surprised me; it confirms, for animals of variable 
temperature, the law established for those of fixed temperature, 
that the number of inspirations is in inverse ratio to the age. 
The use of the tentacular arms of the Sepias was absolutely 
unknown to me until I had the satisfaction to see them in motion 
on a morning of the month of August (1867). A case of the 
aquarium had contained for nearly a month a Sepia of medium 
size, which, during that time, had taken no nourishment. I threw 
to it a rather large-sized fish (Caranx), which swam towards the 
retreat of the Sepia—who had hardly perceived it, when, with 
prodigious celerity and precision, he unrolled and launched for- 
ward his tentacular arms, seized the fish and drew it towards his 
mouth. The tentacular arms then retracted and disappeared, 
but the sessile arms wrapped themselves closely around the 
head and anterior portion of the body of the unfortunate fish— 
which never made a movement after it was caught. The Sepia 
swam about easily in all directions for about an hour, eating the 
while ; it then let the remains of the fish drop to the bottom of 
the aquarium, having opened the skull and devoured the brain 
as well as a portion of the muscles of the back. 
The use of the tentacular arms is then no longer doubtful; 
