JOURNAL 



OF THE 



ROYAL MICROSCOPICAL SOCIETY. 



OCTOBEE 1882. 



TBANSACTIONS OF THE SOCIETY. 



XIV. — Plant-Crystals. By Dr. Aser Poll 



(Bead Uth June, 1882.) 



Plate VI. 



Plant-crystals were first observed by Malpighi,* and afterwards 

 by all phytotomists. But the earliest researches on their composition 

 and anatomical distribution in many plants were made by Sanio 

 (1857). Grulliver has also published, from 1859 to 1880, several 

 papers on plant-crystals, and especially on their classificatory signifi- 

 cance, but I am sorry to have found his works very little known, 

 although they contain a great many very important observations. 

 Holzner ('Flora,' 1864-69) studied the chemical composition, the 

 crystalline shapes, and physiological significance of plant-crystals ; 

 and the other authors who have dealt with the subject are quoted 

 in my work 'I cristalli di ossalato calcico nelle piante,' Boma, 

 1882. 



I. The Composition of Plant-crystals. — We may say that 

 almost all plant-crystals are of calcium oxalate. There are 

 crystals of calcium phosphate and tartrate, of potassium oxalate, 



EXPLANATION OF PLATE VI. 



Figs. 1 and 2. — Kosanoff crystals in Mercurialis annua L. 

 Fig. 3. — The same in the pith of Canothus Africanus L. 

 3bis. — The same in the pith of Lavatera arborea L. 

 4. — Crystals of Salvia rectiflora Vis. 

 5. — Crystals of S. janthin i, Otto et Dtetr. 

 6. — Crystals of the Solanacese. 

 7. — Vertical sections. A, in a female flower of Bicinus; B, in a male 



flower ; c, crystals ; /, fibro-vascular bundles ; p, peduncles ; 



s, sepals ; I, petals. 

 8. — A, transverse section of the petiole of a seed-leaf of young Sicinus ; 



B, vertical section of the same ; g, glands ; /, fibro-vascular 



bundles ; t, vessels ; c, crystals. 



* Opera omnia, Lugduni Batavorum, 1687. 

 Ser. 2.— Vol. II. 2 S 



