STRUCTURAL RELATIONSHIP 279 



3. Acalephae 



4. Polypi 



5. Infusoria 



In 1801, Lamarck introduced a new term "Inverte- 

 brata" and a new idea, that of physiology, into classifi- 

 cation; he also made a revision of Cuvier's classification, 

 leaving the vertebrates unchanged. 



Invertebrata. 



I. Insensitive Animals Class 1. Infusoria 



2. Polypi 



3. Radiaria 



4. Tunicata 



5. Vermes 



II. Sensitive Animals Class 6. Insects 



7. Arachnids 



8. Crustacea 



9. Annelids 



10. Cirripeds 



11. Conchifera 



12. Mollusks 

 Vertebrata. Class 13. Pisces 



14. Reptilia 



15. Aves 



16. Mammals 



The employment of function as the correlative of struc- 

 ture in classifying animals was overdone by Oken, who, 

 in 1810, published the following classification of the 

 Invertebrates : 



Grade I. Intestinal Animals. 



Cycle I. Digestive Animals Radiata 



Class 1. Infusoria (stomach animals) 



2. Polypi (intestine animals) 



3. Acalephas (lacteal animals) 

 Cycle II. Circulative Animals 



Class 4. Acephala (biauriculate animals) 



5. Gasteropoda (uniauriculate ani- 

 mals) 



6. Cephalopoda (bicardial animals) 



