750 THE AMERICAN NATURALIST. [VOL. XXXVIII. 



granular protoplasm eliminates them as structures immediately 

 concerned with the form of a cell or organ thus limiting their 

 functions more especially to metabolism. 



6. The Ccenogamete. 



The cxnogamete is a multinucleate sexual cell. The name 

 was first applied by the author (Davis, : oo, p. 307) to the 

 remarkable multinucleate eggs of Albugo bliti, and the concep- 

 tion has been considerably extended since, as explained in his later 

 writings on Saprolegnia (Davis, : 03, p. 320-331) and on "The 

 relationships of sexual organs in plants" (Davis, : 04^). Ste- 

 vens ('99) discovery of the multinucleate eggs of Albugo bliti 

 opened a field of research that has been greatly extended in the 

 past four years and which is likely to yield very important con- 

 clusions on the relationships and evolution of the Phycomycetes 

 and Ascomycetes. Conditions similar to Albugo bliti were 

 reported the following year by Harper, : oo, for Pyronema, and 

 several later papers have described, with greater or less fullness, 

 the structure and behavior of ccenogametes in some other Asco- 

 mycetes, types of the Peronosporales (species of Albugo) and in 

 the Mucorales. 



We shall not discuss the details of these investigations with 

 their bearings upon the problems of phylogeny as this has 

 become a very complicated subject and is treated elsewhere 

 (Davis, : 04 a-b~), but merely describe the structure and behavior 

 of ccenogametes so far as they are known to us. 



Stevens and Harper both found that the multinucleate female 

 cell of Albugo bliti and Pyronema was fertilized by the introduc- 

 tion of a large number of nuclei from the antheridium. These 

 sexual nuclei paired off and fused, a male with a female, in the 

 common mass of cytoplasm so that the fertilized cell finally con- 

 tained a large number of fusion nuclei. A similar history was 

 reported later by Stevens (:oi), in Albugo portulacae and Albugo 

 tragopogonis . These events have been so thoroughly studied 

 that we know the processes of fertilization in the above forms as 

 well perhaps as for any plant type. 



The structure and especially the nuclear history of other 



