Prof. Bailey on the Crystals found in Plants. 29 



SALicACEiE, Salix. Bunches occur in the parenchyma of the 



leaves of several species of Willow, while form A 

 predominates in the veins and liber. 



Taxace^, Salisburia adiantifolia. Veins of leaf very beautiful- 



ly shown in the ashes by rows of large crystalline 

 bunches. 

 Taxus Canadensis. Bunches in bark. 



TiLiACEiE, Sparmannia Africana. Bunches exceedingly abun- 



dant, with some crystals of form B. 



Urticace^, Ficus carica. If a portion of the pulp of the Fig be 

 compressed between plates of glass, and examined 

 by the microscope, beautiful vascular bundles of 

 spiral vessels, and latex vessels, will be seen, and 

 exterior to these, are rows of cells, with large 

 bunches of crystals. 



Valerianace^, Centranthus rubus. 



VaccinacejE, Vaccinium resinosum. 



Note. — In tables A, B and C, I have recorded the results of the ex- 

 amination of most of the dicotyledonous plants in which I have detected 

 crystals. I have not recorded the experiments in those cases where I 

 have not been able to detect the crystals, as I attach less importance to 

 merely negative results. Still there are some families in which I am 

 almost certain that they are not to be found, notwithstanding the state- 

 ment of Unger, quoted by Quekett,* that all families contain them, 

 and that they are present even in Ferns, Mosses, and the lowest Algae. 

 I have repeatedly examined various plants of the great families Com- 

 positse, Labiatese, Graminese, Filices, Musci and Algae, by all the meth- 

 ods which readily showed crystals in other plants, and as yet have not 

 detected a single crystal in any one of them. 



The crystals in the bunches (form C) are usually so crowded, 

 that it is often impossible to determine the form of the single 

 crystals, but in some cases, as in hickory, (figures 15 and 16,) it 

 is possible to find bunches showing pretty distinctly the forms of 

 the simple crystals of which they are made up, and thus enabling 

 us to see that they result from aggregations of forms allied to B 

 or A. In other cases a projecting angle may be measured, or 

 else by crushing the bunch, some of the crystals may be 

 separated, so as to be examined more carefully. All the ex- 

 aminations which I have made in this way have led me to the 



* See Q.uekett's paper on Raphides, in Lindley's Introduction to Botany, sec- 

 ond edition. 



