Royal Society. 457 



of a peculiar construction, passing transversely, and forming loops, 

 which are situated between the caeca of the stomach, and which are 

 studded by an immense number of small rounded bodies closely con- 

 gregated together, and bearing a great resemblance to the structure 

 of the venae cava* of the cephalopodous Mollusca. The purpose an- 

 swered by this structure is involved in much obscurity : the author 

 offers a conjecture that they may be analogous in their office to the 

 mesenteric glands of the higher animals. 



With a view to determine some circumstances relating to the mode 

 of the respiration of the leech, the author made some experiments, by 

 confining the animal in water deprived of air by boiling. After some 

 time the leech was observed to give out bubbles of air j and the water 

 of the vessel, when tested by lime-water, indicated the presence of 

 carbonic acid. — The paper is accompanied by drawings of the struc- 

 tures described. 



3. " On the Comparative Osteological Forms in the Adult Euro- *»*j£ 

 pean Male and Female of the Human Species." By Walter Adam, 

 M.D., Fellow of the College of Physicians of Edinburgh. 



With a view to the future investigation of the osteological deve- 

 lopment of the human race, the author gives, in the present paper, 

 the results of a great number of measurements, which he has very 

 carefully made, of the dimensions of the different bones composing 

 the adult human skeleton. The male bones examined were those in 

 the collection of Dr. Monro ; the female bones were furnished by 

 Dr. Hamilton. The author was anxious to fix on some one dimen- 

 sion in the skeleton which might be taken as the standard of all the 

 measurements : and finding that no bone of the trunk or limbs pos- 

 sessed the requisite characters for that purpose, he sought for it in 

 the cranium 5 and the result of an extensive series of observations 

 led him to adopt as the standard of measure the distance between the 

 prolongations ot the zygomatic ridges, immediately over the meatus 

 auditorius externus, as being that dimension which was less liable to 

 variation than any other of the human cranium. This line he deno- 

 minates the auricular transverse j and, adopting a scale of which the 

 unit is the 14th part of this line, being generally about the third of 

 an inch, he states at length, in multiples of this unit, the dimensions, 

 in different directions, of almost every bone in the skeleton ; noting 

 more especially the differences that occur in those of the two sexes. 

 Of these measurements, which are given in much detail, and in many 

 instances arranged in a tabular form, it is impossible to give any 

 abridgement. The conclusion he deduces from his inquiry is, that 

 every bone in the body exhibits certain modifications, according to 

 the sex of the individual. 



4. " Some Experiments and Observations on the Combinations of 

 Carbonic Acid and Ammonia." By John Davy, M.D., F.R.S. 



The author was led to the investigations of which he gives an ac- 

 count in the present paper, by finding in the note-books of his brother, 

 the late Sir H. Davy, some memoranda of experiments which he bad 

 made on the salts of ammonia, and more especially on the carbonates. 

 The first part of the paper relates to the direct comoination of car- 



Third Series. Vol. 3. No. 18. Dec. 1833. 3 N 



