﻿1903] OOGENESIS IN SAPROIEGNIA 235 



violet. The protoplasmic structures are so minute as to require 

 lenses of the clearest definition, and the Zeiss apochromatic 

 objectives 2"^"^ and 1.5""^ with the compensating oculars were 

 employed throughout the investigation. 



OOGENESIS. 



i 



■ The accounts of nuclear and cytoplasmic activities in Sapro- 

 legnia during oogenesis present some striking contradictions, 

 and leave untouched some phases of a detailed but very signifi- 

 cant character, Humphrey (1892) was the first author to 

 apply methods of cytological technique, cutting sections In 

 paraffin, and his studies were followed by the investigations of 

 Trow (1895, 1899) and Hartog(i895, 1896, 1899). The last 

 two authors have expressed very divergent views, asserted with 

 a positiveness that invests their discussions with an atmosphere 

 of personal criticism that need not be reviewed in this paper. 

 It is necessary, however, to consider certain conclusions of the 

 earlier authors with which the present writer is not in accord, and 

 it seems best to do this at the outset, leaving the points of agree- 

 ment with the present investigation to be taken up in their 

 proper' connections. 



It is well known that the oogonium of the Saprolegniales 

 contains many times more nuclei than the number of eggs ulti- 

 mately formed. Humphrey and Hartog believed that the nuclei 

 fused with one another, thus reducingr the sum total until the 

 s requisite number was present. Trow stated that the number was 

 diminished through degeneration and digestion until it was so 

 small that each ^^g took but a single nucleus. The writer has 



found no evidence of nuclear fusions as reported by Humphrey 



and Hartog, and in general supports Trow's view of degenera- 

 "tion. However, there seems to be a reason, not known to Trow, 

 for the selection of the fortunate nuclei destined to preside over 

 the eggs, and a large part of this paper will deal with that 

 subject. 



It is also well known that the eggs of the Saprolegniales are 

 > not infrequently binucleate, and sometimes trinucleate. Hum- 

 phrey and Hartog considered such conditions as merely the final 



