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MESSRS. E. M. BALFOUR AND W. N. PARKER ON THE 
Anteriorly tire two kidneys are separated by a short interval in the median line, but 
posteriorly they come into contact, and are so intimately united as almost to constitute 
a single gland. 
A superficial examination might lead to the supposition that the kidney extended 
forwards for the whole length of the body-cavity up to the region of the branchial 
arches, and Hyetl appears to have fallen into this error; but what appears to be its 
anterior continuation is really a form of lymphatic tissue, something like that of the 
spleen, filled with numerous cells. This matter (Plate 26, fig. 60, ly.) continues from 
the kidney forwards without any break, and has a colour so similar to that of the kidney 
as to be hardly distinguishable from it with the naked eye. The true anterior end of the 
kidney is placed about 3 centims. in front on the left side, and on the same level on the 
right side as the wide anterior end of the generative duct (Plate 26, fig. 60, ocl.). It is 
not obviously divided into segments, and is richly supplied with malpighian bodies. 
It is clear from the above description that there is no trace of head-kidney or 
pronephros visible in the adult. To this subject we shall, however, again return. 
As will appear from the embryological section, the ducts of the kidneys are probably 
simply the archinephric ducts, but to avoid the use of terms involving a theory, we 
propose in the anatomical part of our work to call them kidney ducts. They are thin- 
walled widish tubes coextensive with the kidneys. If cut open there may be seen on 
their inner aspect the numerous openings of the collecting tubes of the kidneys. The} 7 
are placed ventrally to and on the outer border of the kidneys (Plate 26, fig. 60, sg.). 
Posteriorly they gradually enlarge, and approaching each other in the median line, 
coalesce, forming an unpaired vesicle or bladder (bl.)— about 6 centims. long in our 
example—opening by a median pore on a more or less prominent papilla (u.g.) behind 
the anus. The dilated portions of the two ducts are called by Hyrtl the horns of 
the bladder. 
The sides of the bladder and its so-called horns are provided with lateral pockets 
into which the collecting tubes of the kidney open. These pockets, which we have 
found in two female examples, are much larger in the horns of the bladder than in the 
bladder itself. Similar pockets, but larger than those we have found, have been 
described by Hyetl in the male, but are stated by him to be absent in the female. It 
is clear from our examples that this is by no means always the case. 
Hyetl states that the wide kidney ducts, of which his description differs in no 
material point from our own, suddenly narrow in front, and, perforating the peritoneal 
lining, are continued forwards to supply the anterior part of the kidney. We have 
already shown that the anterior part of the kidney has no existence, and the kidney 
ducts supplying it are, according to our investigations, equally imaginary. 
It was first shown by Muller, whose observations on this point have been confirmed 
by Hyetl, &c., that the ovaries of Lepidosteus are continuous with their ducts, forming 
in this respect an exception to other Ganoids. 
In our example of Lepidosteus the ovaries (Plate 26, fig. 60, ov.) were about 18 
