592 APPENDIX. 



EXPLANATIONS OF THE PLATES. 



PLATE I. 

 Figs. 116 : see 14. 



Fig. 1. Contents of the embryo-sac of Vicia faba soon after fecundation. In 

 the clear fluid, which consists of gum and sugar, swim granules of protein com- 

 pounds (a), amongst which are some of a larger size. Around these last the first 

 are rolled together so as to form a little disc, and sometimes two such discs are 

 seen blending one with the other (6). Around other discs can be discerned a clear, 

 sharply-defined edge (c), which gradually extends further from the disc (thec}to- 

 blast), and at last may be clearly distinguished as a young cell. 



Fig. 2. Young and very irregular cells from the albumen of Vicia faba, with 

 beautiful parietal cytoblasts and nuclei. 



Fig. 3. Free cytoblasts in the sac of the embryo of Sanguinaria canadensis ; three 

 of them are hollow (?), with a firm nucleus. 



Fig. 4. Cytoblasts with nuclei from the embryo-sac of Pimclea drupacea : 

 a, Free cytoblast with nucleus; b y a cytoblast with two nuclei ; c, cytoblast with 

 three nuclei, and the cell forming around it. 



Fig. 5. Cytoblasts from the sac of the embryo of Fritillaria imperialis, in various 

 stages of development. 



Fig. 6. Some cells from the albumen of the same plant, having a correct rela- 

 tive size to the foregoing figure. The cytoblasts are partly round (a) and partly 

 lenticular (6) ; they are always, through a peculiar substance, firmly adherent to 

 the wall. 



Fig. 7. Cells from the albumen of Pedicularis palustns. rr, The single wall of the 

 cell; b y section of the surface of the cell in focus. Around the cytoblast is seen 

 a great quantity of a muco-granular substance, which moves in little reticular 

 streams on the inner surface of the wall. 



Fig. 8. Mature pollen-grain of Frilillaria imperialis, with parietal cytoblasts ; the 

 great central cavity is the result of endosmosis. 



Fig. 9. Formation of the fermentation-fungus in currant-juice (page 37.). 

 a. The first appearance of solid matter (protein ?) in the clear juice. These 

 globules pass gradually into the forms at b. These are found suspended in the 

 juice when it begins to become opalescent, and before the slightest trace of the 

 development of gas or of fermentation can be detected ; b and c are transitionary 

 stages ; rf, e,f, ferment-cells in various stages of increase. 



Fig. 10. Decomposition of pure protein in a solution of sugar (during fermenta- 

 tion), page 37. a. A small portion of protein breaking up into granules (b} at the 

 under part; d, a portion of protein, with the edges well defined on one side, and 

 at the other breaking up into little granules, from which proceeds, indistinctly at 

 its commencement, a little cellular fibre ; c, various forms of cellular fibres pro- 

 duced in the fermentation of a solution of sugar with pure protein and protein 

 compounds. 



Figs. 11 13. Gradual development of the hairs on the stem and leaves of 

 Glaucium luteum. In the original elongated epidermal cells, transverse cells are 

 formed, which are clearly seen to be free. At a, one of these cells displays two 



