xiv COMPARATIVE ANATOMY 



PAGK 



2. Connective Tissue . . . . • .41 



3. Neuro-musculaii and Muscle Tissue . 46 



4. Nekve Tissue . • ^^ 

 Literature . ... 52 



CHAPTEE II 



METAZOA 



Intboduction . • 54 



Zoophyta or Coelenterata 



Systematic Review . . ■ 58 



Gastrseadse 



Systematic Review . . 58 



Literature . ■ 60 



Porifera 



Systematic Review . . 60 



Literature . . . . 66 



Cnidaria 



Systematic Review . . 66 



1. Genebal . . 73 



2. The Body Epithelium . . . 81 



3. The Gastro-canal System . . 82 



4. Musculature ... 86 



5. Tentacles of the Cnidaria, Maeginal Lobes of the ScypHOMEDUs.E 90 



6. The Nervous System . 92 



7. The Sensoet Obgans . . . . 94 



8. SuppoETiNG Organs, Pboteotive Obgans, Skeleton . . 97 



9. Funnel Cavities (Septal Funnels); Subgenital Cavities, Subgenital 

 Chamber .... ... 101 



10. The Sexual Organs . . 101 



11. The Stratification of the Cnidaria Body . 103 



12. Reproduction ..... . . 104 



13. Oeganisation of the Siphonophora . 108 



14. Life-history of the Cnidaria, Alternation of Generations . 115 

 Literature ......... 117 



The fundamental law of Biogenesis — Egg segmentation and the development 



of the two primary germinal layers of the Metazoa (gastrulation) — The 



ontogeny of the Cnidaria . . . 1X8 



Literature . ... . 132 



