178 



FAMILY: AMCEBID^E 



culture of an amcBba, which she named Vahlkamjpfia patuxent, from the 

 stomach of oysters. Though its method of nuclear division resembled 

 that of Dimastigamoeba gruberi, she failed entirely to obtain flagellate forms, 

 though all the methods which cause Dimastigamoeba gruberi to develop 

 flagella were tried. 



Calkins (1913) separated the amcebse which have this particular type 

 of nuclear division into two genera — viz., the genus VahUamjjfia, to include 

 the forms which do not develop a flagellate stage, and the genus Ncegleria 

 (created by Alexeieff, 1912) for those which have such a stage. The 

 latter forms, as pointed out by Alexeieff (1912a) really belong to 

 the genus Dimastigamoeba of Blochmann (1894), and will be considered 



mm 



• 6 

 Fig. 



90. 



7 8 



Vahlkamiyfia punctata. (After Vaiilkampf, 1905.) 



1, 2. Appearance of living amoeba and encysted form ( x 1,500 ?). 3-8. Stages in nuclear 

 division ( x 3,000 V). 



below (p. 260), and as Chatton and Lalung-Bonnaire actually observed 

 markings which were undoubtedly pores on the cyst wall, it is probable 

 they were dealing with an organism belonging to the same genus. In 

 this case, both the names Ncegleria and Vahlkampfia are really synonyms 

 of Dimastigamoeba. 



As already remarked, it is still doubtful if any of the ama>bfe having 

 the type of nuclear division of Dimastigamoeba gruberi are really incapable 

 of developing the flagellate stage. The majority, at any rate, have not 

 been investigated from this point of view. Most of these forms are free- 

 living amoebae, occurring commonly in damp soil or decomposing vegetable 

 material, but some of them have been found in the intestines of cold- 

 blooded animals. Others are to be regarded as coprozoic amwba?, as they 



