366 SUMMARY OF CUEEE^'T RESEARCHES RELATING TO 



Amoeba Proteus. — Lucy A. Carter {Proc. Roy. Phys. Soc. 

 EdMurgh, 1919, 20, 193-210, 1 pi.). A careful studj of amoebte 

 referable to A. proteus shows the existence of three "types," which are 

 described and designated as A. proteus X, A. proteus Y, and A. proteus Z. 

 These three " types " should not be given new specific names until 

 there is more certain proof that they are distinct species, rather than 

 phases in the life-history of one species. If they can be separated as 

 species, older names should be preferred to new ones, thus A. proteus 

 Pallas (A'), A. princeps Ehrenberg (Y), A. tiobilis Penard (Z) ; or Y 

 might be called A. proteus Pallas var. granulosa. Schaeflfer's classifica- 

 tion into raptorial and granular amcebge is very useful ; the raptorial 

 type being represented by A. proteus X, the granular types by A. 

 'proteus Fand A. proteus Z. J. A. T. 



Promitosis and Syndiseresis : two Methods of Nuclear Division 

 co-existing in Amoebae of the " Limax " Group. — A. de Zalueta 

 {TraJ). 3Ius. Nac. Gien. Nat., Madrid, Ser. Zool, 1917, No. 33, 52 pp., 

 2 pis. and text-figs.). Wasieleu'sJcia gruheri (Schardinger), an amoeba of 

 the " Limax " group, has two quite different types of nuclear divisions, 

 viz. promitosis and syndiferesis, the former similar to that occurring in 

 other amoebae. Under the name " syndia3resis " is included a complex 

 group of nuclear divisions, consisting of a division giving rise to two 

 daughter-nuclei which, at the moment of separation, are themselves 

 sub-dividing to produce two grand-daughter-nuclei. Thus syudijeresis 

 comprises three inseparably bound divisions, the first called protoditeresii;, 

 and the other two metadia3resis. Syndiaeresis takes place in special 

 pantosome nuclei, which are different from ordinary nuclei and are of 

 unknown origin. All the amoebae observed were taken from cultures 

 derived from a single carefully isolated organism, and therefore belonged 

 to one species. 



The author compares his observations with those of various earlier 

 writers, pointing out that, though Aragao and Belar recognized two types 

 of division, their descriptions differ essentially from those founded on 

 these new facts and recorded under the name of syndiseresis, since they 

 had observed neither pantosome nor metadigeresis. J. E. 



