133 



care the specimens of the female Ornithorhynchus preserved in the 

 Museum of the Royal College of Surgeons, found the structure to 

 correspond very exactly with the account given by Meckel ; and, 

 moreover, succeeded in injecting the ducts of these glands with mer- 

 cury. He further notices the differences of development occurring in 

 five different specimens : the size of these glands having an obvious 

 and direct relation to that of the ovaria and uteri. The gland itself 

 is composed of from 150 to 200 elongated subcylindrical lobes, dis- 

 posed in an oblong flattened mass, converging to a small oval areola 

 in the abdominal integument, situated between three and four inches 

 from the cloaca, and about one inch from the mesial line. It is si- 

 tuated on the interior of the panniculus carnosus, the fibres of which 

 separate for the passage of the ducts to the areola ; the orifices of 

 these ducts are all of equal size, and occupy an oval space five lines 

 in length by three in breadth ; not elevated however in the slightest 

 degree above the surrounding integument. An oily fluid may be 

 expressed from the ducts by squeezing the gland. 



A minute description is then given of the anatomical structure of the 

 internal genito-urinary organs of the female Ornithorhynchus : from 

 which it appears that if the animal be oviparous, its eggs must, from 

 the narrow space through which they have to pass in order to get out 

 of the pelvis, be smaller than those of a sparrow ; and no provision 

 appears to be made for the addition of albumen or of shell in the 

 structure of that part of the canal through which they afterwards 

 descend previous to their expulsion from the body. The ova are en- 

 veloped in a tough fibrous membrane in which the traces of vascu- 

 larity, at least after being preserved in spirits, are not perceptible ; 

 whilst in birds the ova are attached by narrow pedicles, and are co- 

 vered by a thin and highly vascular membrane. 



From the whole of this inquiry, the author concludes that these 

 glands are not adapted to the performance of any constant office in 

 the economy of the individual, but relate to a temporary function. 

 Their total absence, or at least their rudimentary condition, in the 

 male, of which the author could perceive some traces in one speci- 

 men which he examined, and the greater analogy of their structure 

 to a lacteal apparatus than to that of ordinary odoriferous glands, 

 when taken in conjunction with the correspondence of their deve- 

 lopment to that of the uterine system, induce him to believe [that 

 they are to be regarded as real mammae. This view is confirmed by 

 the fact, noticed by Mr. Allan Cunningham, that the young of this 

 animal readily takes cow's milk, and may be kept alive by this kind 

 of sustenance. 



7. "A Physiological Inquiry into the Uses of the Thymus Gland," 

 by John Tuson, Esq. Communicated by J. C. Carpue, Esq., F.R.8. 



The author is of opinion that the thymus gland is intended for two 

 purposes : the one to serve as a receptacle of blood for supplying 

 the chasm in the circulation occasioned by the great quantity sent 

 to the lungs as soon as the function of respiration commences: the 

 other to serve as a receptacle of osseous matter preparatory to the 

 extensive ossification which is carried on in the early periods of 

 growth. 



