TEXT-BOOK OF EMBRYOLOGY. 



N 



FIG. 5. Various types of spermatozoa. A, B, A teleost; C, D, bird; E, F, snail; G, Ascaris; H, 

 an annulate; /, bat; /, opossum; K, rat; L, salamander; M, N, O, P, crustaceans, k, 

 End knob; w, middle piece; u, undulatory membrane. From Kellicott, General Embry- 

 ology. 



