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Mr. R. I. Pocock,



already been stated. Mr. Frank Finn tells me that the display

of the South African Ostrich has already been described and

figured in the Zoologist, by C. Schreiner ; and in the issue of the

Field, for August 31st, 1907, my description published in 1906

was supplemented by an account by Mr. Scherren of two previous

records. One of these was given Mr. A. D. Bartlett (Wild

Animals in Captivity, p. 279) who observed the display of the

South African Ostrich (Stiuthio australis) ; the other was given by

Dr. Paul Kammerer ( Zool. Garten, 1904, p. 203) who described

that of the pink-skinned African Ostrich (,Strut kio came his), the

specimen observed being one of the birds of the Matarieh

Ostrich Farm, near Cairo, which was said to have been trained

by the keeper to show off at command. However that may be,

it is interesting to note that practically the same actions accom¬

pany the display in all the different kinds of Ostriches in which

the phenomenon has been recorded. It may be added that the

Somaliland Ostrich that has come under my notice is called

Struthio molybdophanes and is grey- or blue-skinned like the

South African bird to which it is nearly allied.


I have briefly alluded to the fact that the hen Ostrich, so

far as can be judged by her behaviour, exhibits complete indiff¬

erence towards the displaying cock. Similar indifference on

the part of hen birds of various species has been repeatedly

noticed by myself. It is indeed a matter of common know¬

ledge to many observers of birds ; and this indifference is

one of the most baffling facts to be faced in attempting to

reconcile the phenomena of sexual display with Darwin’s theory

of sexual selection, or rather with that part of the theory which

deals with the mode of sexual selection which Lloyd Morgan has

aptly called Preferential Mating.


Darwin’s idea was that the beautiful ornaments of many

cock birds have been gradually perfected in the course of ages

by the hens preferring to mate, generation after generation, with

those cocks which possessed the most gorgeous colours 011

luxuriant plumes. Thus the brilliantly tinted cock birds secured

mates and transmitted their beauty, sometimes in an accentuated

form, to their young; while the duller individuals were forced

to remain, for the most part, bachelors, and failed to hand on



