Slide showing pedigree diagram of 'Ptosis'. Slide shows pedigree diagram of 'Ptosis'. Slide image is labelled 'Fig. 2. pedigree of ptosis, autosomal dominant'. The chart is explained by the following key: [white square] 'unaffected male' [black square] 'affected male' [two white squares connected with a line between] 'identical twins' [white triangle] 'sex unknown' [white circle] 'unaffected female' [black circle] 'affected female' [small black dot] 'abortion' [arrow] 'propositus'. The term 'ptosis' refers to droopiness of a body part. Late 19th - early 20th century