66 



THE AMEBIC AN NATURALIST [Vol. XLII 



which there is much discussion and controversy at the present 

 time. The rhizopods offer quite as extensive a field for diver- 

 gent opinions and here again it is mainly in connection with 



are being slowly established and with this hnsis the parasitic 

 forms should be comparatively simple to work out. The one 

 remaining important step to be made in working out the life 

 history of the common rhizopod And In ruhjaris has quite re- 

 cently been taken by W. Klpetiewsky," and it is fitting that it 

 should have been made in Hert wig's laboratory, where the first 

 important steps were taken. The author finds that gametic 



described by Schandinn for ( Vntropyxis. and by Schaudinn and 

 Lister for Polystomella. Macrogametes and mierogametes are 



followed step by step. He found f 1 1 rt 1 ie rmo re. that Arcella re- 



these develop fine heliozoa-like radiating psendopodia, upon the 

 ends of which they roll about for a period of from two to three 

 hours. This observation is interesting in the light of the pos- 



