Slide showing hierarchical diagram of what appear to be guinea pigs. Slide shows hierarchical diagram of what appear to be guinea pigs. There are three levels, beginning with two parents of different types, then one child and eight descendants in the third level of varied colours. Small white label in upper left corner reads: 'Newton & Co. 43 Museum St, London WC1.' Title below images reads: 'Fig. 11. - Short, Smooth, Coloured x Long, Rosetted Albino. (After Castle)'. Late 19th to early 20th century