Br Hcrdman on the ''Olfactory TuhercUr 257 



out meeting, and without being coiled. The opening was 

 anterior and central, and the form of the tubercle perfectly 

 symmetrical. 



Fig. 2. 



Several slight variations from this occur, caused by want 

 of symmetry either in the general form or in the curve 

 of the horns ; frequently one of the latter is more strongly 

 bent than the other, which may overlap it slightly, thus 

 rendering the opening oblique. In other cases, still of 

 simple form, one of the horns may be nearly or altogether 

 straight, while the other is curved inwards; this may 

 occur to either horn, and the straighter one may sometimes 

 be inclined slightly outwards at the anterior end, thus lead- 

 ing towards a very marked variety in which the one horn 

 is bent outwards and the other inwards (that is, both in 

 the same direction) to such an extent that their extremities 

 point posteriorly (as in Fig. 1). 



Eeturning to the simple form just described, we find 

 another marked variation (Fig. 2) caused by the horns having 

 been bent suddenly inwards and downwards, so as to be 

 directed towards the posterior end of the organ. 



One form occurs in which the horns, after curving to- 

 wards each other to such an extent as almost to obliterate 

 the opening, suddenly bend anteriorly, and run in that 

 direction for a short distance. This leads into those forms 

 in which both horns bend outwards (or in opposite direc- 

 tions — one to the right, the other to the left) ; this occurs to 

 various extents, and may be symmetrical or not, one horn being 

 frequently longer or more coiled than the other (Fig. 3). 



One form still remains to be mentioned ; it is quite ex- 

 ceptional, and was only noticed once. The right horn is 

 so little developed as not to extend half way up the 

 VOL. VI. R 



