AMEBOID MOVEMENT 



37 



phenomena, for example, were well known, which they are not, 

 those character differences alone would doubtless make a list 

 several times as long as this one. Compare with Figure n. 



This fundamental uniqueness of all the characters of the 

 various species of amebas naturally gives rise to the question as 

 to what is the cause of this condition of affairs. Why and how 



Figure n. ^1, Amoeba proteus in locomotion. Note especially the x 

 longitudinal ridges, a 1 , equatorial view of the discoid nucleus, a 2 , a polar 

 view of the nucleus, a 3 , equatorial view of a folded or crushed nucleus 

 frequently found in large individuals, a 4 , shape of crystals found in this 

 species. B, Amoeba discoides in locomotion, fc. 1 , b 2 , equatorial and polar 

 views of the discoid nucleus, b 3 , shape of the crystals found in the ameba. 

 C, Amoeba dubia in locomotion, c 1 and c 2 , equatorial and polar views of 

 the ovoid nucleus. c 3 -c 10 , shapes of crystals found in dubia. In these 

 drawings only such characters as are of special interest for the purpose 

 of this work are emphasized. Dimensions in microns: A, 600; B, 450; 

 C, 400; a 1 , 46 x 12; b 1 , 40 x 18; c 1 , 40 x 32; a 4 , maximum, 4.5; b 3 , maxi- 

 mum, 2.5 ; c 3 -c 10 , maxima, 10 to 30. 



