EXPLANATION OF FIGURES. 
Fig. i. Diagram representing primitive nebula, the arrows 
indicating direction of rotation. 
Fig. 2. Diagram representing first ring thrown off'by rotating 
nebula, i, Central mass. 2, King. 3, Denser portion of ring. 
Fig. 3. Diagram representing the breaking of a ring through 
the aggregation of matter about the denser portions. 
Fig. 4. Diagrams of an amoeba, a low form of animal consist¬ 
ing of single “cell” of protoplasm, illustrating the appearance 
of living matter—its structure and the peculiar transformations of 
shape of which it is capable. 
Fig. 5. Diagram illustrating development of bacteria. 1, 
Globular bacteria. 2, The same, after enlargement, constriction, 
and separation into two individuals. 3, Rod-shaped bacteria. 
4, The same, after elongation and formation of spores. 
Fig. 6. The essential parts of a flower. 1, Pistil. 2, Stamen. 
3, Petal. 4, Sepal. 5, Torus or receptacle. [After Gray.] 
Fig. 7. 1, Diagram of incurving leaf, to illustrate formation 
of pistil. 2, Pistil cut transversely, to show two ovules in situ. 
Near upper end of pistil, the union of incurving edges of the 
original leaf is incomplete, leaving an orifice through which, 
later, the fertilizing tube of pollen-grain may descend. [After 
Gray.] 
Fig. S. Diagram representing pistil opened by longitudinal 
section, to show ovule ready tor fertilization. 1, Nucleus of ovide, 
invested by its two coats. 2, Embryonal sac. 3, Embryonal 
vesicle. 4, Pollen-tube. [Modified from Gray.] 
Fig. 9. Diagram of the plant-embryo, at different stages, 
during germination of the seed ; 1, Representing the cellular struct¬ 
ure. 2, The actual appearance. [After Gray.] 
Fig. 10. Diagram representing egg of chicken. 1, Albumen. 
2, Yolk. 3, Germ-cell. 
Fig. 11. Diagrams to illustrate developement of germ-cell. 
The yolk is presented in transverse section, without its investment 
of albumen. A, Germ-cell has enlarged, and divided into two. 
