VOLUME XXXVIII NUMBER 2 
BOTANICAL: Gazer 
AUGUST, 196¢ 
OOGENESIS IN VAUCHERIA. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
BRADLEY MOORE DAvVvISs. 
(WITH PLATES VI AND VII) 
THERE have been published two accounts of the development of 
the oogonium of Vaucheria, attempting to explain in fundamentally 
different ways the final uninucleate condition of the structure at the 
maturity of the egg. All authors have found the young oogonium 
multinucleate, and the problem has concerned the history of these 
nuclei as the egg developed and the oospore matured. BEHRENS 
(90), in partial agreement with Scuitz’s opinion that the material 
discharged from the opening of the oogonium represented a polar 
body, believed that the final single nucleus of the egg resulted from 
the fusion of numerous nuclei in the oogonium. KLEBAHN (’92, p. 
237), in criticism of the results of ScumitTz and BEHRENS, held that the 
egg and oospore were multinucleate. OLTMANNS (’95) came to very 
different conclusions. He described the gradual withdrawal of all 
the numerous nuclei found in the young oogonium from that struc- 
ture into the main filament, with the exception of one which was left 
to become the nucleus of the egg. 
The view of BEHRENs was in general similar to those of HUMPHREY 
and Hartoc for Saprolegnia, since the latter writers believed that 
the numerical reduction of the nuclei in this form was the result of 
successive nuclear fusions. The explanation of OLTMANNS has no 
parallel in any process of oogenesis known to the writer. Neither 
of these accounts seems to be correct, and the processes of oogenesis 
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