I enclaese such a two-dimensional diagram “based on the ( 
differnces in motivation which you sent me for tXK Franklin s 
gull. It may well be that you have already evolved this 
method yourself. I think it is the logical outcome of your 
factory chimney representation. In fact ooth Desmond and I 
arrived at it independently while I was on the Fames and he was 
in Oxford. But I think that his method is slightly less generalised 
than it should be. There seems no advantage in restricting 
as he does the spa.ce over which the motivations produce a posture. 
In any case this is a mere detail. The essence of tne method 
is the representing a pair of factory chimneys by a point on 
the graph. 
6*CGr 
Have you been driven to the conclusion that an® has in 
the kittiwake that the particular quantities of attack and 
escape motivation which give rise to a particular posture are 
different in male and female. I suppose one must conclude 
this when you see: that the greeting is very similar if not 
identical in its main form but that the male is iar 'more 
to attack the female, and she to flee;, than vicej/ersa. 
Presumably it is something li v e this which maxes the ma e ola h- 
hcadel gull'head flag first ?? It can hardly he that he is 
more frightened of the female than . she of him. Or could tue 
sex drive rear its ugly head at this point ? 
No more for now. 
about your work from the 
firs t one . 
Shall write 
summaries . 
again when we hear more 
ilany thanks again for the 
rr.k« 
