Abstract
Wistar rats of the inbred CPB-WE and the random bred Cpb:WU strains have been used in neuro-anatomical studies. In both groups of rats a high incidence of hydrocephalus was observed. In the CPB-WE rats the ventricular dilatation was accompanied by optic tract lesions and microphthalmia. The present report describes the gross and microscopic findings in these rats and discusses the possible aetiology.