Vol. XI, 

 igu 



Correspondence. 



141 



description of the eggs ol Acaiilhiza teiiiiirostris. A and B are 

 alike — 0.57 x 0.43 ; but this (h)es not show the actual jxjsition or 

 ])oint of the diametral measurement, which would be ascertained 

 by means of a formula, and |)rol)al)ly ilejjicted as here shown ■ — 



Although the dimensions are given as the same, in all proba- 

 bility the eggs are dissimilar. The object of the three diametral 

 measurements is to illustrate this graphically. The formuhe arc 

 relative to the particular set of eggs under examination ; con- 

 sequently, every set examined will have its own series of formuhe. 

 We could proceed to describe eggs as follows : — 



Formula of Fig. i. 



2.0 I 



No. in Set. — Two. Shape. — (a) elongate-oval : {b) oval. 



Surface. — Dull, &c. Texture. — Smooth, &c. 



Ground Colour (refer to formula). — A. — Basal area {a) blue, 

 shading to light blue in sub-apical (c), and then to white in apical 

 area {d). 



Underlying Markings. — Almost invisible, greyish, &c. 



Surface Mayki)igs. — Lineal, streaky, &c. 



Colour of Markings. — Green, &c. (or No. of colour chart). 



Disposition of Markings. — A. — Forming a distinct zone in the 

 zonal area (b). B. — Zone mostly in zonal, and overlapping 

 slightly into basal area (a). 



From descriptions here given, it is possible to draw, and fill in, 

 the characteristics of eggs. The terms I have provisionally pro- 

 posed would, I venture to think, be of inestimable value, as defined 

 areas would get rid of a lot of confusion in relation to descriptions, 

 being preferable to such terms as " larger " and " smaller " 

 end. Basal, zonal, sub-apical, apical, would always stand for 

 a particular position in all eggs, and their use would always develoj) 

 a mental picture of that part of the egg they denote. 



Shape. — Consistency is requisite in the adoption of terminology 

 relative to shape. Ovate, oval, elongate-oval, elliptical, rotundate, 

 &c.. could be fixed in relation to the greatest diameter and length. 



Surface and Texture require set terms. 



Colour of Markings and Ground Colour. — The colour chart will 

 obviate all difftculties. and make possible a uniform description. 



Underlying and Surface Markings — It is important to establish 



