506 MR. J. S. HUXLEY ON THE 
position that one would naturally call Jemale) on the open water. 
Thirdly, either cock or hen may assume this position on the nest 
or pairing-platform. This is important, for the pairing-platform 
is never ascended except for the purpose of pairing, or for this 
position, which we may call the beginning of, or the invitation to, 
pairing, and the nest only ascended for these two purposes and for 
incubation. Fourthly, when one bird is in the passive position, 
the other, be it cock or hen, may come up to it, examine it, and 
make as if to leap up on to it, just as it often does before an 
actual attempt at pairing is made. The natural end of this 
sequence would be that, fifthly, either cock or hen might not 
only make as if to ascend into the active position, but actually 
do so. If the text-books are right in their descriptions of the 
sexes in the species, then we can say that this end has been 
reached, and that, as far as pairing-positions go, the sexes are 
interchangeable. If the text-books are wrong, then our evidence 
is simply insufficient. Here it can only be shown that, however 
incredible this reversal may appear, yet it is quite certain that 
in the Great Crested Grebe all the preliminary steps towards 
it have been already taken. 
Further, Selous (loc. cit.) places on record some remarkable 
facts which show that reversal of pairing-attitude does take place 
in tame Pigeons. Here he several times saw, immediately after 
the act of pairing, the “male” bird crouch, and the ‘“ female” 
then get into the normal male attitude. The act of pairing was 
then gone through a second time, but with the attitudes of the 
birds reversed. See also Selous ’02. 
We have therefore evidence that the full reversal can take 
place, aud now only want to be certain that it has taken place in 
this species. In any case we can say that characters (in this case 
attitudes and actions only) of the female have been transferred to 
the male, as well as characters of the male to the female. 
We must now go on to consider a very different question, 
which is also well brought out in the pairing-habits of the Great 
Crested Grebe: I mean the gradual change of a useful action 
into a symbol and then into a ritual: or, in other words, the 
change by which the same act which first subserved a definite 
purpose directly comes later to subserve it only indirectly 
(symbolically), and then not at all. The action in question 
here is the passive pairing-attitude, and the Grebe is interesting 
as showing all three stages of the process at one time—the 
passive attitude employed sometimes directly, sometimes sym- 
bolically, and sometimes ritually. Speaking phylogenetically, 
we have the following steps :— 
(1) The ascent on to a nest or platform, and the assumption 
of the passive attitude, are necessary if pairing is to take place, 
and the passive bird must get into position before the active 
bird can even begin its part in the coition act. 
(2) The ascent and the attitude are used by the passive bird as 
