1908 - 9 .] 
713 
The Skeleton of a Sowerby’s Mfiiale. 
In all the specimens the three cartilaginous proximal elements, racliale, 
intermedium, and ulnare, were present. In one the intermedium and 
ulnare were in process of fusion with each other, but the pisiform cartilage 
was recognised in only the two smallest. In three specimens (B, C, D) five 
disto-carpalia were seen, of which C x was blended with the base of M I} but 
the fusion was not sufficient to obliterate the primitive separation; C 2 
articulated with M n ; C 3 , usually the largest, articulated with M in ; C 4 
with M IV ; C 5 for M v was distinct in specimen (C), but in B and D it was 
in process of fusion with carpale 4 . In the smallest foetus (A) C x was 
distinct from Mi, but C 5 was not differentiated, and possibly had hot been 
developed as an independent unit. A and B had an os centrale in the 
interval between the radiale, intermedium, and carpalia 2 and 3 , which in B 
had the form of a rounded nodule continuous with the distal border of the 
intermedium. In the largest foetus (D) the centrale was most distinct and 
in process of fusion with C 2 , though the original line of separation was 
apparent. In a paper on the carpus of Beluga, published in 1893, 
Ktikenthal referred to an embryo of Monodon monoceros, 24 6m. long, in 
which he saw two centralia.* 
I may also state that Leboucq in his memoir described three foetuses of 
Beluga, in each of which he found a well-formed centrale ; in one it was 
free between the radiale, intermedium, and C 2 ; in another it was in 
process of fusion with C 2 ; in the third it was partially fused with the 
radiale. 
In the collection of cetacean limbs presented to me by Sir John 
Struthers were three specimens of the Narwhal, in one of which, an adult, 
the radio-ulnar epiphyses were fused with their respective bones ; but in 
the other two the ossification was not so complete. The adult was dissected 
4 
by Professor Struthers, who, so far as I know, did not publish a description 
of it.f Radiograms of the three hands were taken for me by Mr Ernest 
Henderson. That of the adult has greatly assisted me to determine the 
constitution of the carpus : in it the bony radiale was 26 mm. in transverse 
diameter ; the intermedium, deeply grooved on both surfaces, was 37 mm. ; 
the ulnare was 26 mm. wide. In the distal row a piece of cartilage 
separated the radiale from Mi ; in the radiogram it was seen to have in its 
substance a small nodule of bone, and it probably represented C x , which was 
* Morphologisches Jahrbuch , vol. xix. p. 63, 1893. 
t At the Aberdeen meeting of the British Association, September 1885, Professor 
Struthers exhibited the carpal bones and cartilages of several cetacea, including the 
Narwhal, but his description was not published. See Report of meeting, p. 1056. In the 
Journal of Anat. and Phys., vol. vi. p. 115, 1872, he referred in a footnote to the fibrous 
arrangements replacing muscles in the hand of the Narwhal, but did not speak of the bones. 
