ZOOGENY. 373 



The number of the sensitive vertebrae is consequently 

 7X5=35, which are distributed into three groups, in 

 accordance with the principal cavities of the body, whereof 

 Jthe 2 terminal groups consist of 15, but the abdo- 

 minal group, which combines or unites them, only of 5. 

 The body is accordingly not merely laterally, but also in 

 length, a perfectly symmetrical structure, which has been 

 parcelled out in the following manner into its five stock- 

 works, stories or floors : 



I. Dermal vertebra. 



A. Sexual vertebrae. 



a. Coccygeal vertebrae 5, 



b. Sexual vertebrae . 5, 



c. Pedal vertebrae . 5. 



B. Abdominal vertebrae . 5. 



C. Thoracic vertebrae, 



a. Pulmonary vertebrae 5, 



b. Brachial vertebrae . 5, 



c. Cervical vertebrae . 5. 



II. Auditory vertebra . 1 . 



III. Lingual vertebra. . 1. 



IV. Optic vertebra . . 1 

 V. Nasal vertebra . . 1. 



This regularity is found too only in the human skeleton. 

 The animals are irregular men. (Vide Oken's Zahlen- 

 gesetz in den Wirbeln. Isis, 1829, S. 306.) 



Cavities of the Trunk. 



2115. The osseous system forms the trunk or body, 

 because ft follows the vascular system ; the two other 

 galvanic systems, the dermal and intestinal systems, form 

 the large portions of the trunk or its cavities ; to them is 

 added the sexual cavity or pelvis. 



2116. There are thus three truncal cavities, a pul- 

 monary, an intestinal, and a sexual cavity, or thoracic, 

 abdominal, and pelvic cavity. 



2117. The osseous system will develop itself most 

 feebly around the abdominal, because it is the indifferent 

 cavity. Therefore there are either no ribs at all, or they 

 are so short that they do not reach to the anterior 



