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The rudimentary copulatory organ of the domestic fowl
Author(s) -
MacDonald Elizabeth,
Taylor Lewis W.
Publication year - 1933
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.1050540302
Subject(s) - biology , cloaca , phallic stage , penis , fowl , anatomy , gonadal ridge , sex organ , zoology , embryo , ecology , embryogenesis , psychology , genetics , psychoanalysis , microbiology and biotechnology
The rudimentary copulatory organ of chickens was first observed as a phallic knob in 6‐day embryos. This phallic knob enlarged similarly in both male and female embryos up to the twelfth day: from the twelfth to the seventeenth day it was distinguished by a large process in the males and a diminishing process in the females. Further differentiation took place from the eighteenth to the twenty‐first days: some females lacked the porcess, others retained a smaller process than that of the male. As growth advance, fewer females retained the process until at 12 weeks of age it had entirely disappeared. The process was found in all males and showed no retrogression, whereas the few capons examined lacked it. A ridge‐shaped ‘pseudo’ process developed at about 1 week in some females and was present up to 3 weeks of age. Histologically and embryologically, the process was seen to possess some characteristics of a penis. The cloacal method of sex determination might be used with an average maximum accuracy of about 90 per cent in living day‐old chicks.