482 



DR. G. LINDSAY JOHXSON ON THE 



[June 5-, 



chief varieties met with in this country, were examined hy me 

 with the same degree of luminosity and classed according to the 

 shape of their pupils, as shown in the following table, in which I 

 use the terms relating to shape in the sense hereinafter indicated 

 and illustrated. 



I examined the animals twice over, first hy day-light, and then 

 by gas-light, the results on both occasions being the same. 



Tortoiseshell. 



Number 

 examined. 



Round. 



Nearly 

 round. 



Round 

 oval. 



Pointed 

 oval. 



Short-haired Cats 

 (Males) 



30 



33 



14 

 4 

 2 



25 



7 



22 



29 

 14 



20 

 17 



13 

 3 

 



19 



4 

 1G 



15 

 4 



1 



2 



1 

 l) 

 



1 

 1 

 



2 

 2 



4 



9 





 1 

 1 



2 



i 



5 



10 



7 



5 



5 





 

 1 

 3 

 1 

 1 



2 

 1 



Short-haired Cats 



Short-haired dark-blue 

 and silver-grey tabbies. . 



Siamese Cats (Males) 



„ „ (Females)... 



Long-haired Cats (Males) 

 Long-haired Cats (Fe- 





Total 



180 



111 



10 



40 



19 





Fig. 1. 



I understand by : — 



Bound — Practically a perfect circle. (Fig. 1, a). 



Nearly round or Obtuse round — The area common to two equal 

 circles whose centres are separated by not more than a ^ 6 part of 

 their diameter, (b.) 



Round ovcd or Rectangular oval — The common area formed when 

 the circles are separated by about g part of their diameter, (c.) 



Pointed oval or Acute oval — The common area formed when the 

 centres of the circles are separated by 5 or more than a quarter of 

 their diameter, (d & e.) 



It will be seen by the above table that no general rule can be 

 established as regards variety, with the exception perhaps of the 

 blue tabbies, in which no oval pupils were observed. 



The colour of the iris seems to have no bearing whatsoever on 

 the shape of the pupils. Sex likewise does not seem to be any 

 guide, as the following summary of the above table shows : — 



