44 PROCEEDINGS OF THE ACADEMY OP 



of the Proteus is rt-dactylous, and it is found that the third toe 

 is the median ray of a divergence terminating the ulnar projec- 

 tion. 



In this connection reference was made to Buhl's 1 account of a case 

 of congenital defect in the human foot, in which four toes only 

 were present. The missing toe was the fourth, which is the median 

 terminal divergent of calcaneal side of foot ; the normal arrange- 

 ment of the human foot being as follows: The potential side 

 (tibial (?), remembering the twist of the posterior extremit}-, 

 caused the speaker to consider the potential side of the foot to be 

 homologous with the ulnar side of the hand) is segmented twice 

 (astragalus and scaphoid) to produce three divergents (1st, 2d, 

 and 3d metatarsals), each of which segments four times in form- 

 ing the first three toes. The outer weaker side segments serially 

 twice (calcaneum, cuboid) to yield two divergents (4th and 5th 

 metatarsals), which thence form the fourth and fifth toes. 3 



The relations between the term actinapophysis and the term 

 ray, as used in the above descriptions, were next dwelt upon. It 

 was proposed to restrict the term actinapophysis to a segment 

 projected from the side of an axial ray, while such axial rays are 

 always in themselves projections from a hypothetical non-osseous 

 centre. It follows that unless a ray can be traced to such centre, 

 it cannot be considered of primal value, and becomes actinapo- 

 physal. In the event of the correctness of this hypothesis, many 

 of the identifications of Parker must fall. 



Actinapophyses may behave like primal rays with respect to 

 the bone from which they spring. The separately ossified tip to 

 the acromion process is an example. This is an interesting ex- 

 pression of an actinapophysis projecting in an opposite direc- 

 tion to the axis of its own ray. Huge, 3 in his descriptions of 

 abnormalities of the acromion, figures two disjuncted actinapo- 

 physes in the above position. They are, it was judged, the 

 two centres of ossification of the acromial tip, not co-ossified 

 axiall}', as is the rule, but placed as divergents to the primal ray. 



Dr. A. felt inclined to claim for such centres the name of " cen- 

 tres of nutrition," and to revert the present application of the 

 theory to Goodsir* (1845). 



1 Congenital absence of femur, etc. Zeit. f. Rat. Med., 1860, p. 128. 



2 In the hand the radius (ulna, Gegenbaur) yields the scaphoid for a 

 segment, and the trapezius and trapezium as divergents (probably). The 

 ulna gives the semilunar for a segment and magnum unciform and cunei- 

 form for divergents ; the fourth and fifth toe are secondary divergences 

 from the unciform (probably). 



s Zeit. f. Hat. Med., 1859, p. 258. 



1 k 'Of the forces which exist in connection with centres of nutrition 

 nothing very definite can yet be stated. When this branch of inquiry 

 shall have been opened up, we shall expect to have a science of organic 

 forces bearing direct relations to anatomy, the science of organic forms." 

 An. and Path. Obs., Art. Centres of Nutrition. 



[June 25, 



