SKELETON. 



661 



is altogether obliterated. By this circum- or post sphenoid vertebra, the cranial basis 

 stance of the body of the sixth or occipital is contracted in its longitudinal axis, while 

 cranial vertebra joining the body of the third the cranial vault (fig, 481.) fashioned of the 



Fig. 482. 



The base of the human cranium, 



Showing its serial relation with the bodies or centra of the spinal vertebrae, and also the serial 

 homology between the foramina of the cranial vertebra? and those of the spinal vertebrae. 



expanded neural arches, affords ample space 

 wherein to locate the crescent organ of the 

 intellect. 



PROP. XL. The scapulary or fore-limbs of 

 all the vertebrated animals are homologous to 

 one another. The variety among these organs 

 occurs by a metamorphosis or omission of ele- 

 mentary quantity. The right scapulary organ 

 is perfectly identical with the left in the same 

 animal body. Both the fore-limbs of the 

 human body are identical ; those of other mam- 

 mals are identical ; those of a bird are iden- 

 tical ; those of a reptile are identical ; and 

 those of a fish are also identical. Os- 

 seous quantity is equal for both fore- 

 limbs of the same animal. But the fore- 

 limbs of all animals are not quantitatively 

 equal, far from it. The fore-limbs of a mam- 



mal differ by quantity from the fore-limbs of 

 a bird, those of a bird from those of a 

 reptile, and those of a reptile from those of a 

 fish. The mammal fore-limbs manifest a 

 quantitative difference amongst all species of 

 that class ; the avian fore-limbs the same ; 

 the reptilian fore-limbs the same ; the 

 piscean fore-limbs the same also. The ana- 

 tomist who would undertake the task of re- 

 cording the quantitative difference manifested 

 amongst all the fore-limbs of the vertebrated 

 classes, would require a chart as free as space 

 and a leisure as unconfined as time. As 

 quantitative difference is of such infinite ac- 

 count, I shall not therefore record it by the 

 numerical method ; but my task shall rather 

 be to develop that idea in generalisation, 

 which will interpret the infinity of variety as 

 u u 3 



