Rutland. — Bight- sidedness. 339 



If P be any point (a/3y), and P' its isogonal conjugate, then 

 (i) expresses that PP' passes through the fixed point (a /3 y ), 

 (ii) expresses that PP' is parallel to the line la-\-m[34-ny = o, 



. a j3 y 



and (iii) expresses that PP' touches the conic — +77 +— = 0. 



Such curves as the above possess the property that the 

 tangent at any point transforms isogonally into a conic touch- 

 ing the curve at the isogonal conjugate of the point of contact 

 of the tangent. 



Art. XXXII. — Right- sidedness. 



By Joshua Rutland. 

 Communicated by T. W. Kirk. 



[Bead before the Wellington Philosophical Society, 1th August. 1907.] 



Plate XXIV. 



Soon after the red deer became sufficiently numerous in the 

 Pelorus bush to justify the Marlborough Acclimatisation Society 

 issuing shooting licenses I commenced collecting heads of all 

 ages, regardless of their appearance, my object being to studv 

 the growth of the horns. 



Many of the heads that came into my possession appeared 

 deformed, owing to the right and the left horns differing much 

 in size and outline. This want of symmetry I soon perceived 

 was common to animals of every age, from fawns with simple 

 horns to old stags with many-branched antlers. 



Looking over a collection of these unsymmetrical heads 

 to ascertain whether there were any marks of violence which 

 might account for the deformity, I noticed that in all the right 

 horn was larger and better shaped. 



After this discovery I carefully examined every deer's head 

 — shapely or unshapely — that came within my reach, and found 

 that wherever there was a perceptible difference in the size 

 of the two horns the right horn, without exception, was larger 

 than the left. 



The accompanying photograph (Plate XXIV) by Mr. Paul 

 Clifford shows two fawns' heads and the head of an old stag, 

 in all of which the greater size of the right horn is very con- 

 spicuous. The fourth head, at the top of the picture, appears 

 quite symmetrical from a short way off, but a closer examina- 

 tion shows the right horn is stouter than the left. Several 



