Figs. 54, 55, 56, and 57 are a series of transverse sections through the genital
ridge and mesonephros of one side from a larva of 11 centims.
Fig. 54. Section of the lymphatic organ which lies in front of the
mesonephros.
Fig. 55. Section near the anterior end of the mesonephros, where the
genital sack is completely formed.
Fig. 56. Section somewhat further back, shewing the mode of formation
of the genital sack.
Fig. 57. Section posterior to the above, the formation of the genital
sack not having commenced, and the genital ridge with primitive
germinal cells projecting freely into the body-cavity.
Fig. 58A. View of the testis, mesorchium, and duct of the kidney of the
left side of an adult male example of _Lepidosteus_, 60 centims. in length,
shewing the vasa efferentia and the longitudinal canal at the base of the
mesorchium. The kidney ducts have been cut open posteriorly to shew the
structure of the interior.
Fig. 58B. Inner aspect of the posterior lobe of the testis from the same
example, to shew the vasa efferentia forming a network on the face of the
testis.
Figs. 59A and B. Two sections shewing the structure and relations of the
efferent ducts of the testis in the same example.
Fig. 59 A. Section through the inner aspect of a portion of the testis and
mesorchium, to shew the network of the vasa efferentia (_nve_)
becoming continuous with the seminal tubes (_st_). The
granular matter nearly filling the vasa efferentia and the
seminal tubes represent the spermatozoa.
Fig. 59 B. Section through part of the kidney and its duct and the
longitudinal canal (_lc_) at the base of the mesorchium.
Canals (_sc_) are seen passing off from the latter, which
enter the kidney and join the uriniferous tubuli. Some of
the latter (as well as the seminal tubes) are seen to be
filled with granular matter, which we believe to be the
remains of spermatozoa.
Fig. 60. Diagram of the urinogenital organs of the left side of an adult
female example of _Lepidosteus_ 100 centims. in length. This figure shews
the oviduct (_od_) continuous with the investment of the ovary, opening at
_od´_ into the dilated part of the kidney duct (segmental duct). It also
shews the segmental duct and the junction of the latter with its fellow of
the right side to form the so-called bladder, this part being represented
as cut open. The kidney (_k_) and lymphatic organ (_ly_) in front of it are
also shewn.