64 Zoological Society, 



a forced assimilation, among other facts peculiar to the class of Mam- 

 malia; but on the contrary we are under the necessity of placing- the 

 Monotremata further within the limits of oviparous animals. 



V At the other extremity of the scale of beings, where the fishes are 

 placed, we meet with a gland secreting mucus, extending along the 

 sides from the head to the tail. Ascending the scale, we see it sepa- 

 rate into fractions ; some Reptiles, and among others the Salamanders, 

 have it large and forming a continuous band, as in Fishes : we have 

 said in what state it is found in the Monotremata." 



In a postscript, dated February 19th, M. Geoffroy states that at a 

 Meeting of the Academie des Sciences on the previous day, M. de 

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

 on the subject of the Monotremata, and supported the views of 

 Mr. Owen. He states that some contradictions and physiological 

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

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

 details. 



The reading having 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 observations. 



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

 that eminent anatomist at once regarded them as mammary. M. Geof- 

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

 structure is not conglomerate, like that of mammary glands, but 

 lobed and consisting of numerous cceca, resembling the structure which 

 he has described as existing in the odoriferous glands which surround 

 the mamma of the Shrews; hence he concluded that their function is 

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

 these little animals, namely, to secrete an odorous substance for the 

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

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

 mary gland must necessarily be conglomerate, by showing that these 

 organs in the Cetacea consisted of simple cceca, a structure even less 

 complicated than that demonstrated in Ornithorhynchus at a later pe- 

 riod, by Mr. Owen. During his investigation of the structure of 

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

 state of the sexual organs in several individuals which he examined, 

 that they correspond 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, (see p. 60,) with which he 

 conceives the young to be provided when brought into the world ; but 

 this may be regarded as improbable, the tubes, (upwards of a hundred 

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

 the secretions from the glands being so very slender and elongated 



