592 H. p. KJERSCHOW AGERSBORG 



of the genital pores. Fv, female genital vestibule ; Mga, male genital 

 aperture; >iS<, stomach. This section is of particular interest 

 since it shows the two separate openings. xl5. 



Fig. 78. — Microphotograph of a cross-section of the penis. Ig.lp, 

 glandular lining of the penal cavity ; Lin, lumen ; Og.lp, glandular cover 

 of the penis ; Ms, musculo-fibrous part of the penis. 



Fig. 79. — Microphotograph of a cross-section of the body in the region 

 of the female genital duct, showing the many corrugations of the uterus 

 ( Ui). Mg, mucous gland ; Pro, prostata ; St, stomach. X 14. 



Fig. 80. — Microphotograph of a cross-section of the uterus, showing 

 semen in its lumen (Sem). F, uterine pocket ; Gl, glandular lining ; 

 Ms, muscular wall, x 42. 



Fig. 81. — The organs of reproduction in Melibe leonina. Bil.dpr, 

 biluminate ampullo-prostate duct ; Amp, ampulla ; Cl.p, penal cleft in 

 the mucous gland ; Mgl, mucous gland ; Od, oviduct ; O.sp, ovisperma- 

 totheca ; Ot, ovitestis ; P, penis ; Pr,* prostata ; Sv, seminal vesicle of 

 the penis ; Ut, uterus ; Va, vagina ; Fe, vasa efferentia. x 2. 



Fig. 82. — Drawing of portion of a cross-section of the ovispermatotheca. 

 Bni, basement membrane ; Ept, tall columnar epithelium lining the organ ; 

 Mf, nmscle-cell cut longitudinally ; Nu, nucleus ; Nuco, nucleolus ; 

 Kar, chromatin granules ; Lin, linin ; Mic, micromeres ; Myf, myo- 

 fibrillae ; Ret, reticular structure or axial myofibrillae ; L, loose con- 

 nective-tissue cover. 



Fig. 83. — Drawing of part of a cross-section of the penis. Cil, cilia ; 

 Cc, connective-tissue cells ; Excpl, external epithelial cover of the penis ; 

 lepl, internal epithelial lining of the organ ; Lnt.ml, internal fibrous layer ; 

 M, miicous substance ; Oc, lining of the penal cavity, x .36. 



Fig. 84. — Drawing of a few cells from the mucous gland, showing the 

 gland to be composed of taU columnar epithelium with a short ciliated 

 border. Bg, basal granules ; Bm, basement membrane ; Ctc, connective- 

 tissue capsule ; Fch, free ciliated border of the internal surface of the 

 gland ; Mic, micromeres ; Nu, nucleus, small and shrunken ; Pcini, 

 nucleus of actively filling cells ; Rs, reticular structure of cells in the state 

 of refilling. The cells in A are in a state of exhaustion. They stained 

 poorly with Delatield's haematoxylin. B represents a condition prior 

 to liquefaction of the granula. Note the nuclear membrane seems to be 

 wanting and there are a number of small chromatic granules near the 

 nucleus. The nucleus (Pom) is filled with uniformly sized chromatic 

 bodies. The nucleolus being in some cases irregular in shape. C represents 

 cells like A and B, but in C the micromeres [mic) are larger than in A, 

 and the nucleus not quite so shrunken. That is, these cells are in a state 

 of refilling. D, cuboidal epithelium from a loop of a non-glandular part 

 of the organ. 



