64 Mr. Morgan's Description 



ture, at which part the two structures were inseparably united. 

 On making a section of the tube, I found that its cavity was 

 nearly half filled with a secretion precisely resembling that 

 already described as lubricating the interior of the pouch, and 

 that its internal surface was formed by a reflection of cuticle 

 continued from the surface of the pouch through the aperture 

 by which it opened into that part. 



At the furthest extremity of the canal, and at the part already 

 described as connected firmly with the gland itself, its termina- 

 tion was formed by a rounded papilla, which projected into its 

 interior, resembling in miniature the extremity of the future 

 teat in the adult. On making a section of the papilla, this 

 resemblance was still further increased by the exposure of nu- 

 merous minute vessels, which presented very much the appear- 

 ance of lactiferous tubes, and which passed directly from the 

 expanded base of the papillary projection to its extremity {tab. 2. 

 f.2.d.). By an examination of the extremity of the papilla 

 through a lens, the similarity between that part and the teat of 

 the adult was strikingly shown. From these circumstances, I 

 considered that the identity of this structure with the future 

 teat was rendered more than probable ; and it occurred to me, 

 that the only mode by which a development of the organ could 

 take place, must consist in the complete eversion of the canal, 

 and the consequent protrusion of its previously imbedded and 

 papillary extremity. 



The canal on the opposite side had not yet been opened : 

 with a view, therefore, of producing an artificial eversion by 

 mechanical means, I made pressure upon that point of the 

 gland, which I knew from previous dissection to be closely 

 connected with the papillary extremity of the tube, and suc- 

 ceeded at length in completely everting (through the opening 

 already mentioned) the whole of the canal, from one extremity 



to 



