PLATE 86 



Solitary Crystals 



1. Quassia (Picrcena excelsa [Swartz.], Lindl.). 



2. Uva-ursi leaf (Arctostaphylos uva-ursi [L.], Spring.). 



3. Quebracho bark (Aspidosperma quebracho-bianco, Schlechtendal). 



4. Wild-cherry bark (Prunus serotina, Ehrh.). 



