Agrica

Topological organization of the olfactory region of the forebrain of Indian house wall lizard has been studied by Eager's method. The olfactory lobes which join with olfactory bulb by elongated olfactory tract. Like other terrestrial vertebrates, the wall lizard also possesses a dual olfactory system viz. (a) olfactory proper, (b) accessory olfactory bulb. In the longitudinal vertical section, the accessory olfactory region has been differentiated which projects to amygdaliod nucleus. In the transverse section of olfactory region two lobes of proper olfactory region and two small lobes of accessory olfactory bulb are clearly visible. Both olfactory and the accessory olfactory nerves and the olfactory and accessory olfactory bulbs are paired and bilaterally symmetrical. These olfactory nerves terminate in either the principal olfactory formation or accessory olfactory formation of the olfactory bulbs at the rostral end of telencephalon.

The olfactory bulb is located at the anterior end of the telencephalon which is pointed in the anterior most part and broader at the base. From the anterior pointed end of the olfactory bulb olfactory nerves comes out. The olfactory bulb is connected to telencephalon by olfactory peduncle. In both transverse and longitudinal sections the fibers of olfactory bulb are seen directly connected with the olfactory cortex.

There is a little difference between accessory olfactory bulb and main olfactory bulb except that the accessory olfactory bulb is smaller than the main bulb. The different layers of accessory olfactory bulb are not clearly visible. The fibers of accessory olfactory bulb seem to connect the amygdala region of cerebral hemisphere.