"Forms of spermatozoa (not drawn to scale). 1 and 2. Immature and mature spermatozoa of snail; 3. of bird; 4. of man (h., head; m., middle portion; t., tail); 5. of salamander, with vibratile fringe (f.); 6. of Ascaris, slightly amoeboid with cap (c); 7. of crayfish." -Thomson, 1916

Spermatozoa

"Forms of spermatozoa (not drawn to scale). 1 and 2. Immature and mature spermatozoa of snail; 3. of…