PENIS. 
they are firmly attached. The trabecule are 
most abundant in the middle line of the 
organ, where they are extended in a vertical 
direction from the middle line of the infe- 
rior to the middle line of the superior wall, 
forming a partial septum between the two 
lateral halves of the corpus cavernosum. The 
median partition is most complete posteriorly ; 
in front it is very deficient, and being com- 
posed of parallel tibrous cords, between which 
the cellular structure of the two sides of the 
organ communicate, has given rise to the idea 
from which it received its name of septum 
pectiniforme. The fibrous cords of the corpus 
cavernosum serve, by means of their attachment 
to every point of the interior of its fibrous 
tunic, to equalise the pressure of the circula- 
tion during erection, and prevent the undue 
distention of its walls. The fibrous tunic is 
variable in degree of thickness in different 
parts of its extent; thus it is thin upon the 
crura penis, and is thin also in the situation of 
the inferior groove and at its extremity; in the 
two latter situations it is pierced by several 
vessels which communicate with those of the 
corpus spongiosum and glans penis. 
fhe cellular structure of the corpus caver- 
nosum is composed of a plexus of dilated 
veins, which communicate with each other so 
freely as to represent, when divided by a sec- 
tion, a perfect network of cells separated from 
each other by membranous parietes. The aree 
of these venous cells are smallest near the cir- 
cumference of the corpus cavernosum, where 
they are separated by a greater thickness of 
parietes, and greatest in the centre of each la- 
teral half, where the intervening septa are thin 
and membranous. The veins are lined in their 
interior by a continuation of the common in- 
ternal coat of the veins, and the interspaces be- 
tween them are occupied by contractile fibrous 
tissue. The contractile fibrous tissue is dis- 
posed in parallel fibres separated to unequal 
distances by common areolar tissue ; it is most 
abundant in the thicker parietes of the veins of 
the circumference of the corpus cavernosum, 
and is diminished to two or three fibres in the 
thinner walls of the central veins. The fibres 
are straight in their direction, and arranged 
transversely with regard to the cylinder of the 
corpus cavernosum. Upon meeting the cy- 
linder of a vein in their course they diverge 
at an acute angle, and continue their straight 
direction until again obstructed by another 
vein, when they again separate without exhi- 
biting any tendency to converge and enclose 
the vein. At the point of divergence they are 
crossed by other fibres at the same angle, but 
coming in a different direction, so that the 
parietes between each vein are formed by nu- 
merous fibres of this tissue, crossing each other 
at the angles of interstice between three or four 
veins, but straight and parallel between every 
two contiguous veins. The contractile fibrous 
tissue is remarkably abundant in the horse, 
where, from the redness of its hue, it resembles 
muscular substance; in man it is not abun- 
dant but very distinct, and in some situations 
I was enabled to detect it encircling the cylin- 
VOL, III. 
913 
ders of the veins, and forming as it were an 
additional coat to those vessels. 
The contractile fibrous tissue of the corpus 
cavernosum has been made the subject of con- 
troversy between several of the physiologists 
of Germany, on account of its resemblance to 
muscular substance and the absence of other 
attributes of muscular fibre. It is described 
by Miller in the 48th number of the Medici- 
nische Zeitung des Vereins fiir Heilkunde in 
Preussen, as a peculiar, red, fibrous substance, 
and in the Archiv for 1835* he speaks of it as 
a “substance having a fleshy muscular appear- 
ance, of a pale red colour in the penis of the 
horse, and also in the dog and man. . It forms 
an irregular network of columns (Balken) dis- 
tantly resembling the network and trabecular 
structure of the muscular columns of the 
heart.” His next inquiry was to determine the 
nature of this substance. ‘To decide,” he 
says, “whether a reddish fibrous tissue be 
muscular or otherwise, there are three modes,— 
the microscope, chemical re-agents, and expe- 
riment on the living body. In vivisection of 
the horse, dog, and ram, I saw no contraction 
of this substance under the influence of the 
galvanic current. The results of microscopic 
investigation in the horse are unfavourable to 
the opinion that it is muscular, for the fasci- 
culi present no indication of the characteristic 
transverse strie of muscular fibre, for although 
the transverse strie be indistinct on the mus- 
cular fasciculi of organic life, they nevertheless 
exist. In stating the results of chemical in- 
vestigation, I must remark that I speak solely 
of this peculiar substance as examined in the 
horse, and not of that of any other animal or 
ofman. To render these experiments accurate 
and certain, it is necessary to remove from the 
tissue every particle of tendinous fibre which 
may pervade it, for this, as we shall perceive, 
has a very different chemical composition. In 
chemical characters, the substanice under con- 
sideration does not belong to those tissues which 
afford gelatine by boiling, as is the case with 
tendinous, cartilaginous, and cellular tissue; 
for, after seven hours’ boiling, I was unable to 
extract from the pure tissue, separated from all 
foreign substances, the slightest trace of gela- 
tine. By boiling we obtain a substance preci- 
pitable by infusion of galls, which does not 
gelatinize, but gives off.a powerful odour of 
osmazome. It agrees with muscular fibre and 
fibrine in being precipitated from a solution in 
acetic acid by ferro-cyanate of potash, and 
differs in this respect from the class to which 
cellular tissue, tendinous tissue, and elastic 
tissue belong, for these are not invariably pre- 
cipitable from a solution in acetic acid by ferro- 
cyanate of potash. It would, however, be 
incorrect to deduce the conclusion that this 
tissue must therefore be muscular, for there 
exists an entire class of substances whose solu- 
tion in acetic acid is precipitable by ferro- 
cyanate of potash, such as albumen, fibrine, 
muscular tissue, and corneous tissue.” 
* Page 28, in his report for the preceding year, 
in reply to a misapprehension on the part of 
Krause. 
3.N 
