[ 113 ] 



®n 6ome iProtcin Cr^stalloiba an^ their 



probable IRelation to the IRutrition 



of the pollen«*^ube. 



By Lily H. Huie, Hollywood (Edinburgh). 

 Plate V. 



Y the use of special fixing and staining methods, 

 Zimmerman* has, during the last few years, greatly 

 extended our knowledge of Protein Crystalloids ; 

 and Stock, t using the same methods, has recently 

 investigated their relation to the metabolism of the 

 plant. Apart altogether from those found in 

 aleurone grains. Protein Crystalloids may be clas- 

 sified according to their position in the cell as — 

 I. — Nuclear Crystalloids. 

 2. — Cytoplasmic Crystalloids. 

 3. — Cell-sap Crystalloids. 

 4. — Chromatophoric Crystalloids. 



Nuclear Crystalloids.- — Zimmermann has found that, in the 

 nuclei of Pteridophyta and Angiosperms, Protein Crystalloids are 

 of much more frequent occurrence than was formerly supposed. 

 He has found them in a very large number of Ferns and in 47 

 species of Phanerogams belonging to ten different families. 



Cytoplasmic Crystalloids occurring in the body of the cell have 

 been demonstrated only in a very limited number of instances. 

 Much difficulty has been experienced by observers in determining 

 whether such crystalloids really occur in the cytoplasm or in the 

 cell-sap, because of the thickness of their sections. Up till now, 

 in one instance only — that of the potato tuber — have protein 



* Zimmermann, Beitrage zur Morphologic unci Physiologic dcr PJianzen- 

 zelle. Heft I., p. 54, and Heft H., p. 112. 



t Stock, Ein Bcitrag zur A'cnnhtiss der Proteinkry sialic ; Cohn's Beitrage 

 zur Biologic der PJlanzen., Bd. 6, 1892. 



International Journal of Microscopy and Natural Science. 

 Third Series. Vol. VI. i 



