n6 Animal Morphology. 



plant ; also the superior and inferior maxillaries, as limbs, 

 but, as it were, in direction at right angles to the limbs of 

 the sacro-pelvic plant. The teeth and dental apparatus 

 are so many devices, which blend with the sense of force, 

 that are parts of the integumentary membrane, and are 

 supplied with very fine nerves of touch within, like to the 

 digital apparatuses pertaining to the anterior and posterior 

 limbs. 



The scapula, with its supplementary clavicle, is the re- 

 maining plant or foundation upon which the limbs are set. 

 Taking advantage of the hsemal arches, it is almost as highly 

 modified in some of its homologies with the sacro-pelvic 

 plant as the occipito-pelvic plant is with the sacral, and 

 in all points is wonderfully adapted to avoid shocks, and 

 from its muscular adjustments to obtain free and rapid 

 motion with great strength. 



Concerning the homologies, differentiations, and arrests 

 of development that occur throughout the vertebrate series 

 between the fore and hind extremities, it is out of the 

 compass of this paper to supply ; for only so much is given 

 as is sufficient to direct the attention to the extent and nature 

 of the tripartite membrane of the apparatus of the sense of 

 force or weight. 



To whatever intermediate function and use this mem- 

 brane in the economy may be devoted, taken as an entire 

 and complete membrane, its function and end is to interlock 

 segment to segment, so as to secure locomotion in every 

 form and variety in which we see it carried out in verte- 

 brate animals. 



It might be considered that here was a proper place 

 to give an analysis of that most complete and thoroughly 

 worked-out monograph, by Mr. Parker, F.R.S., upon " The 

 Shoulder Girdle;" but, howsoever such an analysis might 

 grace an humble paper of this kind, the tracing of one is to 



