4 



LIST or ILLUSTRATIONS 



FIGURE PAGE 



56. Skeleton of Python Frontispiece 



36. Sperm of Fur Seal (After Oliver) 



37. "Young" Spermatid (After Ballowitz) 



38. S])ermati(l of Fur Seal (After Oliver) 



39. Spermatid of Fur Seal (After Oliver) 



40. Spermatid of Fur Seal (After Oliver) 



41. Spermatid of Fur Seal (After Oliver) 

 43. Development of Sperm of Argas Miniatus (After Casteel) 10, 11 



43. Development of an Ascidian Egg (After Conklin) ... 17 



44. Spinule Cell of Styela Yakutatensis (After Huntsman) . 44 



45. Spinule Cell of Styela Plicata (After Huntsman) ... 45 



46. Spinule Cell of Styela Greeleyi (After Huntsman) . . 46 



47. Spinule Cell of Styela Montereyensis (After Rittcr and For- 



syth) . 47 



48. Spicules of Sponges (After I.ankester) 51 



49. 50, 51. Development of a Spicule (After Lankcster) . 52, 53 



52. Trichomes of Papaver Orientalc (After Cannon) . . . 55 



53. Trichomes of P. Pilosum (After Cannon) .... 55 



54. Trichomes of P. Somniferum (After Cannon) .... 55 



55. Side View of Amphioxus (After Parker & Haswell) . . 95 



57. Tentacle of Halocynthia Johnsoni (Schematic; After Kilter) 98 



58. Acacia Elata 99 



59. Vicia Gigantea KM) 



60. Cassia Sp KM) 



61. Sequoia Sempervirens K)l 



XV 



