Department of Veterinary Anatomy and Histology, College of Veterinary and Animal Sciences, Mannuthy - 680 651, Thrissur, India.
*Part of the Ph.D. thesis submitted by the first author to Kerala Agricultural University.
Prenatal development of the corpora quadrigemina in the brain of goats was studied using 52 foetuses ranging from a crown rump length (CRL) of 1.4 cm (24 days of gestation) to 41.5 cm (full term). During the seventh week, the primordial quadrigeminal plate appeared in the alar plate region of mesencephalon. The neuroblasts from the inner ependymal layer invaded the dorsal marginal zone of the tectum to form the rostral and caudal colliculi. By 76 days of gestation, the tectum revealed numerous nuclear masses. Neurons and glial cells of the tectum were differentiated towards term. Rostral colliculi showed a laminated structure consisting of stratum zonale, stratum cinerium, stratum opticum and stratum lemnisci from outer to inner. Caudal colliculi were homogeneous without any lamination.
