- 13 - 
But at arty renewal of his aggressiveness she once again tries 
to Hold Her bead whore h© cannot reach it. If she ie very 
frightened she- my even point her bill away fro© His herd, though 
Weeping her Hoad very close behind his. This gives the impression 
of trying to hide her face fro® hi© but ©or© probably its reason 
is a preparation to flee. 
As already mentioned the visit of a strange fetal© to a male 
may actually lead to her shunting Hi©. X am not sure yet 
when this happens but it say be that the f esole * a tendency 
to approach the male is an expression of the sex tendency of 
the mounting bird. That she does it so rerely »ey be because 
she is ueus lly too frightened* The female shows no inclination 
to attach the mate or oven £ks to three ten Hitt, so that one 
supposes that Her aggressiveness is not aroused . 
k 
Something Has already been nr. id of the origin of the 
darting posture of the calc but no attempt Has yet been na&e 
to ©;? plain why an unacted ©ale should adopt the remtebent posture 
which' in other s proles w© associate with the female *e ore* 
copulation posture. One would suppose that this posture would 
be" effective in attracting an unpat ©d female only if she showed 
a very strong urge to aounl the male * Apart froo the fact 
that she? cay (occasionally) mount Hiss in spite of groat fear, 
there Is little to support this suggestion* Of 170 mountings 
noted during 195* only IS;! were mountings of the ©ale by the female . 
At the await one mist leave the pro blew Her© but further light 
would certainly b© thrown on it if the causation of reversed 
copulations was understood* 
A ■ mratlvo study of the advert! si H dis lay ©f 
two other species of cormorants oan be sad© from the published 
descriptions. A comparison of these specie,’ a, the European 
Comoran t Pha bft ro core x on rbo and the Brandt Cormorant ILt^gjli 
•C l l i. 
Is revealing. This is not the 
vi $ 0 X 0 $ 
W.4*' till tU1t0 ~ n - h.^-xifiTr-^f ~ i ‘■■Tfiiirj nfrlrr ^ ^ ■ » .. 
place to enter into the details -bit some conclusions ©ny bo 
B«ntioned. When w« try and co^^er© the different die ay* 
it is easy to recognise a aature® which sr similar 
enough for one to suppose they are w homologous M t i.e. they were 
possessed by a common ancestor* For example a,il three ©pee 
advertise in the forward posture wit lj tilted and 1 
raised* But other postured eannet be ho© ised mm « mteaxm 
until ■ we ( let a dLenenta separately* U is then found taat 
the elements Are combined differently In to© three species. 
One is now left with some features in each species '^hlch are 
not accounted for, including the shag a bow and the slow 
waving backwards and forwards of the head ot the co naorant • 
The Brandt cormorant has something -Interned!; to-, the so~e»i-.ed 
Stroke, These tioveaenta differ m&tnly In their speed* two, 
the bow ana strode being abrupt* the other wither Unguid, 
Since there are already indi cations lsjother s. audios that^ 
alterations in rhythm av& Just the sorts of changes wtiioh take 
