174 
the gall-bladder, which are large and form a 
remarkable plexus, enter the glands in the 
right border of the lesser omentum ; and those 
from the left lobe converge to the lymphatic 
glands situated along the lesser curve of the 
stomach. 
The nerves which supply the liver are de- 
rived from the systems both of animal and 
organic life; the former are filaments of the 
right phrenic and two pneumo-gastric nerves, 
and the latter of the solar plexus. The branches 
from the right phrenic nerve descend by the side 
of the inferior cava, to unite with the hepatic 
plexus in the right border of the lesser omen- 
tum. Swan describes a small ganglion, to 
which filaments converge from the right semi- 
lunar ganglion and right phrenic nerve, as being 
the medium of communication between the 
fe teeth nerve and the hepatic plexus. The 
ranches of the pneumo-gastric nerves pass 
between the two layers of the lesser omentum 
to its right border, and pursuing the course 
of the hepatic artery are distributed with 
the hepatic plexus to the gall-bladder and 
along the portal canals. The hepatic plexus 
proceeds from the solar plexus and surrounds 
the hepatic artery to the transverse fissure ; its 
filaments then accompany the branches of that 
vessel to their ultimate termination, and some 
few are observed to ramify upon the portal 
vein. 
Progressive development of the liver in the 
animal series.—The liver in its simplest condi- 
tion is a mere inflection of the mucous lining 
of the alimentary canal, forming a small cecal 
recess or follicle. The capillary vessels rami- 
fying upon the parietes of this follicle pour 
their secretion upon its internal surface, and it 
is thence conveyed to the alimentary canal to 
be mingled with the ingesta. In this its most 
rudimentary form the liver would appear to be 
present in the Laginella, a small cilio-brachiate 
lypus described and figured by Dr. Arthur 
arre.* Upon the stomach of the Laginella 
are seen several minute cceca which open into 
its cavity; they are usually empty when the 
animal has been for some time without food, 
but become filled with a brownish fluid after a 
meal. The next most elementary form of the 
hepatic coecum is seen in the single lengthened 
follicle discovered by Owen in the ascaris ha- 
licoris. This follicle opens into the alimentary 
canal at about calottiedl Wom its oral extremity. 
Among the Annelida, as in the medicinal leech 
(fig. 69, vol. i.) the liver is represented by 
numerous simple ceecal pouches appended to 
each side of the digestive canal. The next 
step in the complication of the organ is ob- 
served in the lengthened filiform tubuli which 
are connected with the sides of the canal in the 
Aphrodita. These are narrow and constricted 
at their commencement, dilating gradually as 
they proceed farther from the intestine, and 
terminating by a small oval sac. In other 
species of the same genus and in the Areni- 
cola (fig. 70, vol. i.) they pons 7H a_ tendency 
to ramify, by developing small ccecal pouches 
* Philosophical Transactions, 1837, 
NORMAL ANATOMY OF THE LIVER. 
from their sides. In these terminal saece 
Pallas discovered a “ bitter fluid, of an oliy 
brown or greenish-black colour,” which 
conceived to be the juices of marine pla 
which had gained admission into the tub 
through their openings of communication ¥ 
the intestine, but which, it is more than : 
bable, was the proper biliary secretion ¢ 
tubes themselves. In the class ects 
hepatic cceca vary in ive ¢ 
from the simple vesicular dilatations ¢ 
upon the digestive canal of the 
splendidula, or the simple cecal tubu 
carnivorous Cicindela, to the numerous ¢ 
follicles of the Dytiscus, or to the more I 
ened tubuli of the Blatta orientalis. Thr 
out the whole of the class the charaeter | 
roe is tubular, the developrens aa 
the tubuli depending upon iarities 
food or habits of the ema Arac 
the cecal follicles are short, and 
at their extremities in a cluster of 
rounded vesicles, which give’ to the ¢ 
lobulated appearance. They are seer 
Scorpion, in fig. 83, c, c, page 204, 
In the class Crustacea, the hepatic organ as 
a higher and more complicated charact 
simple ccecal follicle of Insecta bee 
branched and ramified, of which we © 
good example in the Argulus foliaceus, 
neated by Miiller. In the a ’ 
(fig. 214, 483, vol. i.) the hep 
(te is more branched than’ ini 
and in the Pagurus striatus (fig. 215, pa 
vol. i.) the liver is composed of an extra 
assemblage of ramified follicles. Int 
organ of the Squilla mantis we perceivea re 
able transition from the simple branched a 
mified follicle of the lower Crustacea to t 
forms of the organ in the molluscous” 
Upon the exterior it is lobulated, and 
lobe is composed of a congeries of mit 
bules which appear like granulations upi 
surface. Examined in its interior it prest 
primary dilated sae of considerable size, 
which branch off a number of secondar 
of smaller dimensions, and these le 
studded over every part of their sui 
minute cecal follicles of a rounded form 
the subregnum Mollusca the liver is of 
size, and approaches in external form & 
solid and if ulated organ of vertebrate 
internal conformation we may still trace 
the lower classes a close analogy with the 
fied tubuli of Articulata. Thus im the” 
Gasteropoda the gland is composed of 
pouches, which divide and subdivide 
smaller and smaller follicles and termin 
small dilated sacs. They may be com 
in their disposition to the stem, bra 
twigs, and fruit of a cluster of gra 
liver of this kind is seen in the Helix p 
In the Murex triton the follicular 3 
the organ would appear to be lost. T 
ternal surface presents a lobulated form 
the interior is composed of a delicate sp 
tissue, consisting of larger and smaller 
which may all be inflated from the exer 
duct. This seeming difference in the 
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