Kraemer : The Crystals in Datura Stramonium 39 



In the ovary a very large number of the cells contain cryptocrys- 

 talline crystals (2 X I X I fit) and in the region of the placenta 

 or inner epidermis rosette aggregates (14 fi in diameter) may be 



found. 



It is rather interesting to note that the cryptocrystalline crystals 

 which are found in such abundance in the parenchyma of roots 

 and stems of Datura Stramonium L. are replaced in part in the 

 petiole and nerves of the leaves by prisms, pyramids and rosette 

 aggregates of crystals and that in the lamina the prisms and pyra- 

 mids evidently are united to form rosette- shaped aggregates only. 



Not infrequently do we find in a cell containing cryptocrystal- 

 line crystals a large rosette-shaped mass of what appears to be an 

 aggregate of small hemiedral crystals. 



The fact that we find monoclinic prisms in Hyoscyamus and 

 raphides in some instances in Atropa and Solanum is further indi- 

 cative that all the various forms of crystals in Datura Stramo- 

 ilium L. are likewise of the monoclinic system. 



That there is a close relationship between the different genera 

 of the family Solanaceae is evidenced by the observations that 

 some of the parenchyma cells of some of the elements of nearly 

 all of the genera and species appear to contain hemiedral crypto- 

 crystalline crystals. These are contained uniformly and in greatest 

 amount in the genera of the Solaneae and Datureae and to the least 

 extent in some of the genera of the Cestreae and Salphiglossideae, 

 there being some exceptions to the last groups in Vestia (of the 

 Cestreae) and Anthocercis (of the Salphiglossideae). 



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