SKELETON. 



667 



hind limb, and according to the quantitative 

 variety of these organs we characterise them 

 by the like names. The hand and the foot 

 are radically the same organs, not only in the 

 same body but in all bodies ; and the law 

 which differences these to an infinitude of 

 special character is one of a phaseal quantita- 

 tive degradation, and just as from the integer 

 9 may be proportioned the quantities 8, 7, 6, 

 5, 4, 3, 2, 1. 



The distal segments of the scapulary and 

 pelvic members are differenced by the ope- 

 ration of two laws, viz. that which subtracts 

 quantity by its annihilation, and that which 



fuses plural elements into single parts. In 

 Jig. 486, B. the hands of the sloth present, nu- 

 merically, various different stages of develop- 

 ment. In the immature being, the parts 1, 2, 

 3, 4-, correspond to the metacarpo-phalangeal 

 series of the human fingers ; whereas, in the 

 adult animal, fitness requires that the elements 

 2, 3 should fuse into the bone 2, and thus 

 duality becomes unity. On the contrary, in 

 fig. A. we find the metacarpo-phalangeal 

 series numbering as many as eight distinct 

 elements holding permanently separate ; and 

 I may remark, as a curious fact, that this 

 series of eight elemental parts corresponds 



Fig. 486. 



A, the fore limb of the whale ; B, the paws of the sloth immature and adult. 



exactly to the number of those nuclei from 

 which the metacarpo-phalangeal series of the 

 fore-finger of B fig. 484. is formed. 



PROP. XLII. The sterno-costo-vertebral 

 quantity is a proportional of the dorso-ventral 

 quantity. Every lesser form which manifests 

 an identity with part of a greater form proves 

 this, and nothing completely truthful but this, 

 viz. that the lesser viewed in comparison with 

 the greater, owes its present condition solely 

 to the fact of its having been metamorphosed 

 from such another quantity as the greater 

 form. In the spinal axis of most fishes 

 Nature develops a series of forms like Jig. 487., 

 which I call dorso-ventral, the dorsal half 

 (1, 2, 3, 4) being quantitatively equal to the 

 ventral half (], 2, 3, 4) ; and the distal extreme 

 (1,1) of either half being terminated by fin 

 processes, the palms (6, 6). In the spinal 

 axis of terrestrial animals Nature presents a 

 series of proportionally diverse forms, such as 

 sterno-costo vertebral quantities, &c. ; the 

 dorsal sides of which are not quantitatively 

 equal to the ventral sides, and these latter 

 sides being still further struck proportionally 

 diverse to each other. The difference be- 

 tween the spinal series of the terrestrial 

 animal and that of the aquatic animal being a 

 quantitative difference simply, forasmuch as 

 the former are identical with some element- 

 ary parts of the latter, I here affirm that the 

 lesser spinal quantity of the terrestrial animal 



is a proportional struck by metamorphosis 

 from the greater spinal quantity of the aquatic 

 animal. Let the comparative anatomist follow 

 me in my remarks upon the skeletal axis of 

 the fishes, and he will find that my explana- 

 tion of the natural law of formation shall not 

 outstep the demonstration which Nature her- 

 self offers as self-evidently truthful. 



I point to a segment (fig. 487.) of the fish's 

 spinal axis in that region of the series occur- 

 ring immediately posterior to the thorax. 

 This segment consists of a combination of 

 elemental pieces (4, 3, 2, 1), arranged in sym- 

 metrical superposition upon the dorsal and 

 ventral aspects of the part which we name 

 the vertebral body, or centrum 5. An abso- 

 lute identity prevails between the dorsal 

 elements and the ventral elements. Those 

 of the dorsum terminate in the dorsal fin 

 (1, 6), while those of the venter terminate in 

 the ventral fin (1, 6) ; such segment of the 

 fishes' spinal series is evidently a whole com- 

 plete archetypal quantity, forasmuch as it 

 proves to be symmetrical whichever way I 

 cleave it, whether horizontally or perpendi- 

 cularly, provided the line of cleavage passes 

 through the vertebral centrum (5). If I cleave 

 this archetypal figure in the same modes as 

 Nature herself does, 1 produce forms identical 

 with Nature's forms, and create of it species 

 like the species of Nature. 



Nature cleaves the ventral half (4, 3, 2, 1) of 



