Stomata and their relation to the mesophyll of the leaf (23104240242)

描述：

Description: Slide from a set used to teach biology at Belleville Collegiate Institute and Vocational School, Belleville, Ontario, possibly in the 1920s. The original boxes were labelled 'Junior' and 'Senior', but the contents appear to have been mixed up. Donated to the Community Archives of Belleville and Hastings County by Mike and Sue Mills in October 2015. Date: 1 January 1925, 00:00. Source: Stomata and their relation to the mesophyll of the leaf. Author: Community Archives.