30 



Blainville had read a paper, in \vhich he maintained his former opinions 

 on the subject of the Monotremata, and suj)ported the views of 

 Mr. Owen. He statės that some contradictions and physiolog^ical 

 impossibilities contained in it had been noticed by MM. Dumėril and 

 Serres, in the course of the discussion, but does not enter into any 

 details. 



The reading ha\'ing been concluded of the abstract of the views 

 proposed by M. Geoffroy-Saint-Hilaire in the memoir submitted, 

 Mr. Owen addressed the Society on its subject. The following is an 

 outline of his obsen-ations. 



When the glands in ąuestion were first detected by M. Meckel, 

 that eminent anatomist at once regarded them as mammar)'. M. Geof- 

 froy-Saint-Hilaire objected to this mode of viewing them, that their 

 structure is not congloraerate, likę that of mammary glands, but 

 lobed and consisting of numerous cceca, resembling the structure whicli 

 he has described as existing in the odoriferous glands \vhich surround 

 the mammtE of the Shreivs; hence he concluded that their function is 

 similar to that of the corresponding organs, as he considered them, in 

 these little animali-, namely, to secrete an odorous substance for the 

 purpose of attracting the other sex in the season of heat. M. Ton 

 Baer subseąuently proved that it is incorrect to assume that a mam- 

 mary gland mušt necessarily be conglomerate, by showing that these 

 organs in the Cetacea consisted of simple cteca, a structure even les* 

 complicated than that demonstrated in Ornithorhynchus at a later pe- 

 riod, by Mr. 0\ven. During his investigation of the structure of 

 these glands Mr. Owen proved, by comparing their condition with the 

 statė of the sexual organs in several individuals \vhich he examined, 

 that they coiTespond in the phases of their development with the true 

 mammary glands, their greatest size being attained when the ovaries 

 appear to have recently parted with their contents. The fact of their 

 development being at its maximum at about the time of the birth of 

 the young, evidently indicating the connexion of their function with 

 this period, M. GeofFroy-Saint-Hilaire at first conjectured that they 

 might secrete the earthy matter of the egg-shell, with which he con- 

 ceives the young to be provided \vhen brought into the world ; but 

 this may be regarded as improbable, the tubes, (up\vards of ahundred 

 and fifty in number and opening by as many orifices,) wluch convey 

 the secretions from the glands being so very slender and elongated 

 as to be evidently adapted for carrj'ing fluids. M. GeofFroy-Saint- 

 Hilaire's subseąuent and most recent opinion is that they secrete 

 mucus, which being sąueezed out by the mother in the water, be- 

 comes thereby thickened, and adapted for the aliment of the young ; 

 but Mr. 0\ven remarked that as he had shov'n that similar glands exist 

 in Echidna, animals inliabiting sandy places, and unfitted for goinę 

 into the water, such cannot be their use in Echidna at least, and it 

 may therefore be concluded that such is not their use in Ornitho- 

 rhynchus. 



Mr. 0\ven added, that he had purposely limited his obser\'ations 

 on the present occasion to the theories propounded by M. Geoflfroy- 

 Sąint-Hilairc respec^ing the uses of the abdominal glaud.s of Orni- 



