TBANSACTIONS OF SKCTION D, — DEPT. ANATOMY AND PHYSIOLOGY. 721 



Among the few mammals in wliich tlie ligamentum teres is described as wanting, 

 the author remarks on the parts in the ornithorhynchiis, sloth, elephant, seal, and 

 orang. The narrow Y-shaped recess in the ornithorhynchiis suggests a relation to 

 the triple line of meeting of the three primary bones in development. The condition 

 in the ox, in which the ligament is present, suggests a similar relation. In the 

 young human subject the triple line intersects the recess, but the pubes and ilium 

 each bear only a small part of the recess. 



In the three-toed sloth a recess of good length and breadth is seen in the bone. 

 In the elephant the recess is present, but small in proportion to the size of the 

 acetabulum. Li the orang a good-sized and deep recess is present, running beyond 

 the middle of the acetabulum, and as broad as the pubic or ischiatic parts of the 

 cartilaginous crescent ; the constricted part, leading fi-om the notch, about half as 

 broad. In the duckbUl, sloth, elephant, and orang there is no mark on the femur 

 to indicate the insertion of a ligamentum teres. 



The author finds the ligamentum teres to be present in the Greenland seal, not 

 free but projecting into the joint from the capsule. A dissection showing this was ' 

 submitted to the Section. The ligament has the usual origin and is inserted into 

 a well-marked notch in the margin of the head of the femur. A notch, not an 

 enclosed pit, on the femiir, for the insertion of the ligamentum teres, is seen in various 

 mammals. In the seal, the acetabular recess is occupied by a fatty and synovial 

 body, which also projects beyond the recess, and the projecting ligamentum teres 

 lies against it. 



3. On the Correspondence hetween the Articulations of the Metacarpal and 

 Metatarsal Bones in Man. By Professor Struthers, M.D. 



On comparing the articulations of the bases of the metacarpal bones with those 

 ■of the metatarsal bones, it will be foimd that, numerically and homologically, the 

 correspondence is exact, bone for bone. Besides the great terminal facets for their 

 carpal and tarsal supporting bases, and the lateral facets on both sides of the thu-d 

 and fourth, and on one side of the second and fifth, the second has two corner 

 facets by which it articulates, — in the hand with the trapezium and os magnum, 

 in the foot with the internal cuneiform and the external cuneiform ; and the 

 fourth has a corner facet by which it articulates, — in the hand with the os magnum, 

 in the foot with the external cuneiform. Thus, including the phalanx, the numbers 

 of the articulations of the five metacarpal and five metatarsal bones, from within 

 outwards, are 2, 5, 4, 5, 3. Considering the very different functional adaptation 

 of these homologous bones, this precise correspondence in their articulations is 

 remarkable. Although the details of the articulations of each bone are fully given 

 in the books on anatomy, the above correspondence has been overlooked, an illustra- 

 tion of how little human anatomy is usually, as yet, taught homologically, although 

 thereby the study may be made both more interesting and more simple. ' 



It is uncertain whether the variety occasionally seen of an articular facet 

 between the first and second metatarsal bones is not a residt of civilisation. The 

 absence of such an articulation in the plantigrade human foot seems explicablejby the 

 original fi-eedom of the great toe. 



4. On the Pronephros of Teleosteans and Ganoids. 

 By F. M. Balfour, M.A., F.B.8. 



The author stated that the enlarged anterior part of the so-called kidnev ot" 

 Teleosteans and Ganoids, which is usually held to be the persistent pronephros or 

 head-kidney, was in reality not part of the true kidney, but merely a great mass 

 of lympliatic tissue. From this it follows that the very remarkable part of the 

 larval kidney, known as the pronephros, does not persist in Ganoids and Teleosteans 

 in the adult state ; and since these two groups are the only ones in which this part 

 of the larval kidney has been supposed to persist in the adult, it must now be held 

 that there is no group known in which the pronephros lasts beyond larval life. 

 1881. 3 A 



