Abstract:
The gross morphometric features of mammalian olfactory system components show variations that may be attributed
to dietary and ecological factors. We analyzed volumes and linear dimensions of olfactory brain components (OBC) namely, olfactory
bulb (OB), olfactory tract (OT) and olfactory stria (OS) in an Afrotherian insectivore, the rufous sengi. These findings were then compared
with those obtained previously in dogs (carnivore), goats (herbivore) and humans (omnivore). Volumes, lengths and breadths of the OBC
were compared with those of the cerebral hemisphere (CH) and the whole brain (WB) by working out their ratios (%). In the sengi, the
volume of OBC: WB was 1.03 %, length of OBC: CH = 58.08 % and breadth of OB: CH = 28.97 %. In an earlier report by Kavoi &
Jameela respective values for the above parameters were 0.03 %, 21.47 % & 8.94 % in humans, 0.77 %, 51.87 % & 29.73 % in goats and
1.95 %, 72.30 % & 42.91 % in dogs. These observations suggest that the anatomical design of OBC happens in a manner that mimics an
animal’s level of reliance on the sense of smell vis-à-vis feeding lifestyles, habitat and dynamics of evolution.
