32 



GENERAL EMBRYOLOGY 



VIII 



"| 



' 



FIG. 14. Various forms of 'cells. IV-IX, from Dahlgren and Kepner, X, 

 after Prenant and Bouin. /, II. Human leucocyte, X 350. ///. Human red 

 blood-corpuscle, X 350. IV. Cell from root cap of calla lily, X 350; p, plastids. 

 V. Epidermis of earthworm, showing four mucous cells in various stages of 

 secretion, and CM, cuticle, X 550. VI. Fat cells in skin of chicken; n, nucleus. 

 X 435. VII. Ovarian ovum (oocyte) of cat; cm, cell membrane; mi, micro- 

 somes; nm, nuclear membrane; o, nucleolus; y, yolk alveoli. VIII. Connective 

 tissue cells from the lobster; cy, cytoplasmic mass; pr, cytoplasmic processes; 

 per, peripheral layer of cytoplasm upon which the rigid material of the tissue is 

 laid down. IX. Pigment cell from the peritoneum of the fish, Ammodytes. 

 Fully extended; the processes can be completely retracted. Two nuclei, X 90. 

 X. Stratified epithelium from human pharynx, showing intercellular connections 

 or bridges, X 375. 



