EXPLANATION OF THE PLATES. 



Where no other measurement is given, the figure re- 

 presents the object magnified about 450 diameters, line -ar 

 measurement. 



PLATE I. 



Fig. 1. Parenchymatous cellular tissue, with cell-nuclei from 

 an onion, magnified 290 times. 



2. Matrix of the pollen of Rhipsalis salicornoides. 



3. Do. do. 



I am indebted to the kindness of Dr. Schleiden for the last two delineations. 



4. Cells from the chorda dorsalis of Cyprinus erythroph- 



thalmus. 



5. Cartilage from the point of a branchial ray, from the 



same. 



6. Cartilage from the middle of a branchial ray, from the 



same. 



7. Cartilage from the root of a branchial ray, from the 



same. 



8. Branchial cartilage from the larva of Rana esculcnta. 



9. Cranial cartilage (ethmoid bone) from the larva of 



Pelobates fuscus. 



10. Cells from the crystalline lens of a foetal pig four 



inches long. 



11. An isolated nucleus of the cells of the crystalline lens. 



12. Cells from the crystalline lens of the same fectu-, ex- 



hibiting their prolongation into the fibres of the Lena. 



13. Fibres from the innermost layers of the lens of a pike. 



14. Cell from the epidermis of a species of grass. 



L5 



