182 MERIST1C VARIATION. [part i. 



In the great majority of cases (over 90 per cent., Leichten- 

 STERN l ) of mammae placed on the mammary lines, the supernumer- 

 ary structures are below the normal ones, being then as a rule in- 

 ternal to them, while those found above the normal mammae are 

 less common and are external to the normal mammae. The di- 

 stance separating the normal from the supernumerary mammae 

 (lifters greatly in different cases, and most conditions have been 

 - 11 intermediate between a stage in which the nipple is bifid, and 

 that in which completely separate supernumerary mammae are pre- 

 sented. It is of consequence to observe that there appears to be 

 no case in which a supernumerary mamma is so large as the nor- 

 mal mamma of the same individual. 



The degree to which supernumerary structures of this nature 

 are developed is very various. They may be fully formed mammae 

 with nipples, in the female capable of function ; while in other 

 cases, on the contrary, they may either consist of nipples only, 

 having no distinguished glandular tissue of mammary character in 

 connexion with them, or they may be tumours of mammary cha- 

 racter without nipples or even definite ducts. Between these 

 >Mveral conditions there is no sharp distinction. It appears there- 

 fore that there are two rudimentary or imperfect conditions possi- 

 ble : either supernumerary nipples without recognizable mammary 

 glands, shading off into small warty elevations of uncertain charac- 

 ter, and on the other hand redundant portions of mammary gland 

 without nipples. The latter may be partially connected w r ith the 

 normal mammae or quite separate from them. All these states of 

 imperfection are much more common than the complete super- 

 numerary mammae. 



Fully formed supernumerary mammae have been found above 

 the normal mammae and also below them, the latter being the 

 more frequent position. For those found on the mammary lines 

 the axilla is the highest position and the upper part of the abdo- 

 minal wall the lowest. Of the rudimentary forms, the mammary 

 tumours without nipples occur usually if not always above and ex- 

 ternal to the normal mammae, being generally in or near the axilla. 

 The supernumerary nipples however are in the great majority of 

 cases below and internal to the normal ones. 



Small supernumerary nipples are quite common in Man, but 

 the statistics of different observers £ive various results. Bruce 

 found in 2311 females 14 cases ('605 per cent.), and in 1645 males 

 47 cases (2"857 per cent.). These persons were patients at the 

 Brompton Hospital for Consumption and were not specially ex- 

 amined with a view to this inquiry. Among 315 such persons 

 examined for the purposes of these statistics, 24 cases were seen 

 (7'6 per cent.), 1 being male and 5 female. In 8 cases two extra 

 nipples were present, and one doubtful case of three extra nipples 



1 Not including mammary tumours without nipples in the axilke. 



