Gross observations identify the morphologic alterations in tissues that are visible without the aid of a microscope. This data domain includes changes in organs observed, terminal body weight, and absolute and relative organ weights at necropsy.
This data domain is part of Chemical Effects in Biological Systems (CEBS) database maintained by the National Toxicology Program.
At the link provided is a PDF and one or more folders containing data. The PDF describes the data, file types, and folder structure present.