The several structures in the liver were studied by comparing the differences between ammocoetes (larva form) and adult lamprey (adult form).
Both of ammocoetes and adult lamprey showed double basement laminas within the space of Disse. One beneath the endothelial cell was indistinct and discontinuous. The other, which surrounded the hepatocytic surface facing the space of Disse, was distinct and continuous.
Fat storing cells in the ammocoetes liver contained usually none or only one lipid droplet within their cytoplasm. In the adult lamprey, the number of both fat storing cells and their containing lipid droplets was makedly increased, especially the number of the latter reached usually to ten in maximum.
Bile canaliculi disappeared in the adult lamprey. No junctional complexes on the side of the bile canaliculi were also observed in the adult lamprey.
Gap junctions between adjacent hepatocytes increased in the adult lamprey, while they were rarely observed in the ammocoetes hepatocytes. Lysosomes appeared to converge around the bile canali culi and in the vicinity of Golgi complexes in the ammocoetes hepatocytes. In the adult lamprey, the lysosomes could be merely observed in the vicinity of Golgi complexes. The lysosomes showed a decrease and their amorphous contents were frequently mottled with electron dense granules.
In the cytochemical studies, some of the lysosomes in the ammocoetes hepatocytes showed positive reactions for both of acid phosphatase and peroxidase but no microbodies showing reaction for peroxidase were demonstrated. Lipo somes including giant liposomes consisted of dilated ER filled with electron dense amorphous materials in the adult lamprey hepatocytes.
Many lipid droplets similar to the contents of giant liposomes were observed in the hepatocytes of the late adult lamprey, while neither lipid droplets nor liposomes were observed in the hepatocytes of the ammocoetes liver.

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The number and arrangemen t of fungiform papillae of the mouse tongue were investigated using a scanning electron microscope. Also, the course of main branches of the lingual nerves was detected by serial sections.
1. The mouse had a mean of 47.6±4.6 papillae per dorsal tongue surface with a range of 34 to 61 (N=5) and a mean of 15.2±2.3 papillae per inferior tongue surface with a range of 11 to 22 (N=5).
2. The fungiform papillae were sparsely distributed on t he dorsal surface of the tongue from the tongue tip to a posterior limit at about 3 to 5 mm backward, especially the most densely at the most anterior 1 mm of the tongue.
3. Becaus e chorda tympani nerve fibers to innervate taste buds on the fungiform papillae located in adjacent fungiform papillae, the course of main branches of the lingual nerves corresponded to the distribution of the fungiform papillae.
4. The arrangement of the funiform papillae was symmetrical or asymmetrical. From the observations of the nonpapillated area as a congenital anomaly and the form of the inferior surface of the tongue, it was considered that the arrangement of the fungiform papillae was based on the developmental formation and tongue deformation in fixation.

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By using thirteen adult dogs, the somatotopic localization in the motor trigeminal nucleus, specially references to the proper masseter, improper masseter and temporal muscles, was studied. The motoneurons of these three muscles are localized in the lateral part of the nucleus within its full length. There is a clear dorsoventral localization. The proper masseter muscle is represented ventrolaterally and the improper masseter muscle just dorsal to that of the proper masseter muscle, whereas the temporal muscle is represented dorsally and dorsomedially in the motor trigeminal nucleus. There also is a craniocaudal representation. These representations in the dog are essentially the same in the cat and rat (Mizuno et al.,1974 and 1976). References

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