272 Universitij of Calif oniia Puhlicatioiis in Zoology [Vol. 16 



correctly interpretod. She figures (her pi. 1(5. fig. 11) an equatorial 

 plate without chromatic polar masses. Following this she gives a stage 

 with two chromatic polar masses and two chromosome ( ?) masses, while 

 the next stage has two chromatic polar masses. If division is pre- 

 mitotic it does not seem that an equatorial plate would he formed prior 

 to the formation of the chromatic polar masses. When these are 

 formed, from what do they arise? Again, she figures an individual 

 with an elongated karyosome which is dumb-bell shaped with evident 

 peripheral chromatin comparable to a prophase of promitosis (see her 

 pi. 1, fig. 3, and Dobell, 1914), but she says it is elongated because the 

 amoeba is elongated. A complete series is needed to clear up these 

 discrepancies. 



Glaser (1912 a) figures division for Amoeba iaclnjpodia which in 

 mo.st respects is like that of Naegleria gruheri. He does not find 

 centrioles, but the karyosome becomes a bent dumb-bell, and the 

 peripheral chromatin comes into the angle of the karyosome. The 

 equatorial plate comes from the peripheral chromatin and is probably 

 added to from the karyosome. During reorganization there is an 

 extrusion of peripheral chromatin. Polar caps are not shown, but 

 notches in the chromatic polar masses suggest their occurrence, as 

 pointed- out by Ford (1914). Glaser did not find a fiagellate stage, 

 but since his division figures are so nearly like tho.se of Xaegleria. it 

 is probable that they occur and that he may have been dealing with 

 Naegleria. 



Calkins (1909) figures an Amoeba linia.r which jiroduces exogenous 

 Inids in the manner described for Naegleria. Chromatin extrusion 

 prior to encystment is also very similar. The karyosome has a globe 

 of peripheral chromatin which is given off into the cytoplasm, but it 

 does not take up its position on the nuclear membrane. 



E. syste:matic position 



Several new generic names have been proposed for amoebas of the 

 limax group. Chatton and Lalung-Bonnaire (1912) proposed Vaiil- 

 kampfia for all of these. Alexeieff (1912c) proposed Naegleria as the 

 generic name of limax amoebas in which during division there are 

 voluminous polar masses representing all of the karyosome, and Hart- 

 mannia for those in which there are no polar masses. Calkins (1913) 

 recognizes the genus Vahlkampfia for the limax amoebas in which a 



