FREE-LIVING NEMATODES 



461 



outnumber them; and the number of free-living individuals is 

 so great that they probably constitute one of the important 

 mechanical as well as biological factors in soil, and in the bot- 



1. Lip 



2. Lateral field 



3. Pharyngeal bulb . . . . 



4. Pharynx 



6. Salivary gland 



. Muscular layer 



7. Cuticula 



8. Hair 



9. Esophagus 



10. Cuticula 



11. Nerre-ring 



12. Duct of ventral gland.... 



13. Esophagus 



14. Nerve ring 



15. Ridge in cuticula, 



16. Esophagus 



17. Stria of cuticula 



18. Snb-cuticula 



19. Wing of cuticula 



20. Cuticula 



21. Cardiac bulb 



22. Dorsal field 



23. VaUular apparatus . . 



24. Its radial muscles 



K. Muscular layer 



26. Wall of Intestine 



27. Wing of cuticula 



28. Orum fit to fertilize.... 



29. Blind end ovary 



30. Intestine 



31. Yolk of egg '.. 



32. Nucleus of egg 



33. Shellofegg.. 



34. Internal lateral field ... 



35. External lateral field . . . 



36. Intestine 



37. Copulatory muscle 



38. Wing of cuticula 



39. Copulatory muscle ..... 



40. Intestinal cell 



41. Accessory male organ. .. 



42. Ejaculatory duct 



43. Copulatory muscle 



44. Wing of cuticula 



45. Constriction in spiculum 



46. Right-hand spiculum 



47. Distal end spiculum 



48. Accessory piece 



49. Caudalgland 



60 Left wing of bursa 



61. 1st caudal gland 



62. 2nd caudal gland 



63. 3rd caudal gland 



'64. Muscular wall 



65. Right wing of bursa 



Diagram of Nematode structure. 



66. Cephalic seta 



57. Labial papilla 



58. Pharyngeal rib 

 69. Pharynx or throat 



60. Pharyngeal tooth 



61. Pharyngeal bulb 



62. Salivary gland 



63. Lateral organ 



64. Esophagus tube 



65. Eye, with lens 



66. Excretory pore 



67. Ampulla 



68. Median bulb 



69. Nerve-ring 



70. Ganglion cells 



71. Duct of ventral gland 



72. Duct of lateral gland 



73. A lateral gland 



74. Cardiac bulb 



75. Valvular apparatus 



76. Wing or ridge in skin 



77. Cardiac collum 



78. Cardia 



79. Stomach or intestine 



80. Tessellation of sams 



81. Cuticula 



82. Wall of intestine 



83. Ventral gland 



81. Striation in cuticula 



85. Ripe ovum 



86. Uterus 



87. Unripe ovum in ovary 



88. Spermatozoa 



89. Fertilised egg in uterus 



90. Blind end of ovary 



91. Yolk of egg 



92. Vaginal gland 



93. Vulva 



94. Vagina 



95. Vaginal gland 



96. Lateral field 



97. Seminal vesicle 



98. Wall of same 



99. Spermatozoa 



100. Copulatory muscle 



101. Accessory male organ 

 .102. Ductus ejaculatorius 



: 103. Three pre-anal papillae 

 104. Copulatory muscle 



105. Proximal end spiculum 



106. Pylorus 



107. Anterior ribs of bursa 



108. Anal gland 

 -109. Anus 



10. Post-anal papillae 

 1. Caudalgland 

 12. Median ribs of bursa 



113. Bursa 



114. Posterior ribs of bursa 



115. Duct of caudal gland* 

 116. Terminus 



FIG. 766. 



Above, anterior end of female. 

 (After Cobb.) 



Below posterior end of male. 



toms of lakes and oceans. The aquatic nematode species exist 

 in enormous numbers, in both fresh and salt water, while the 

 number of individuals is past computation. The unavoidable con- 



