802 Miscellaneous. 
On the Anatomy and Physiology of Amphioxus. -. °° 
By M. P. Bert. t alteg 
The existence of Amphioxus has been ascertained, during the 
month of March of this year, in the muddy sands of the basin of 
Areachon, by MM. Fillioux and Lafont. This is the first time, to 
my knowledge, that any one has found it on the oceanic shores of 
France. : 
From March to May all the individuals have the generative organs 
filled with eggs or with spermatozoids in different degrees of develop- 
ment. After this period these organs are empty and atrophied. 
Like all fishes, the Amphiowi are fit for reproduction before they 
have attained their full size. No difference can be ascertained be- 
tween the male and female, even when the generative sacs are filled 
with their products, except with the aid of magnifying-instruments, 
The number of these pouches is, in both sexes, from twenty-two to 
twenty-six; that of the muscular masses is sixty-one pairs; but 
that of the branchial spaces varies considerably with the size, as has 
long been known (an individual of the length of 20 millimetres has. 
93 spaces, one of 30 millimetres 153). This augmentation takes 
place at the two extremities of the branchial apparatus; of this we 
may easily be assured by taking for point of reference the anterior 
extremity of the liver, which always corresponds to the sixteenth 
muscular mass. Beyond the abdominal pore the coats of the body 
do not closely embrace the intestine, as M. de Quatrefages says. I 
have, on the contrary, verified the assertion of J. Miiller, who de- 
scribes a prolongation of the peritoneal cavity going to the anus. 
It is true that the particles which have traversed the branchial net- 
work never get into this passage, which is sometimes obliterated by 
the contractions of the coats of the body. On the other hand, I 
cannot admit the existence of the lateral canal (prolongation of the 
general cavity) which according to some anatomists opens at the side 
of the mouth. | 
Each of the ovarian sacs consists of a thin wall furnished with 
pavement-epithelium, of which the very pale cells measure about 
0:01 millim. ‘Within, separated from the sac by an interval full of 
a transparent liquid, is the ovigerous sac, which is extremely thin 
and without epithelium when the eggs are developed ; but when 
these first make their appearance, it possesses epithelial cells 0-010- 
0°014 millim. These cells group themselves round the young 
eggs, which appear to originate only in contact with the wall. The 
smallest that I have seen were 0:038 millim., their germinal vesicle 
0°009 millim., and their germinal spot 0:004 millim. I have found 
them in the same sac from that size to 0°24 millim., which is that of 
the mature egg (vesicle 0:09, spot 0°026 millim.). The vitellus 
becomes opaque when the egg attains 0°085 millim. I have seen at 
the same time in the sac some isolated corpuscles which had all the 
characteristics of the germinal vesicle. When the eggs are mature, 
they lose their spot and vesicle, and, being compressed in the sac, form 
at its surface an elegant mosaic. ‘They then emerge by the burst- 
ing of the sac and pouch : in the wall of the former some pigment- 
granules are developed; it then contracts and becomes invisible. 
