H. TV. KING ON AM(EB^. 415 



The specimens observed from the West Indies moved rapidly, 

 but in a similar manner to those of the same kind I have seen 

 inhabiting England, by protruding always the pale ectosarc, the 

 normal outline of the pseudopodia of which are rounded at the 

 extremity. When in motion the pseudopodia, controlled by an 

 even impulse, flow like a film, and there is no dividing of the 

 pseudopodia into a fringed outline as is to be seen in those speci- 

 mens (Figs. 1 and 2, PI. XX.) received in a dipping from St. Lucia. 



It is possible that these different forms of Amajbee have gradu- 

 ally adapted their protoplasmic action to the influence of the sur- 

 roundings in the water in which they live, whether they are clayey, 

 flocculent, or covered with the growth of algas or other vegetation, 

 for all these different conditions appear to induce special growth 

 and attributes in Amoebae, that become, under like conditions, 

 exemplified in the different varieties as distinct fixed attributes. 

 The different varieties have a special manner of extending their 

 pseudopodia, of moving their whole mass, and of gliding, and the 

 internal circulation also varies, as does the general appearance of 

 the beings. Amoeba ^9?mc^7;s moves by elongating the pale 

 ectosarc, which has functions of selecting food, of motion of touch 

 and of adaptation. It would seem to possess special powers in 

 these respects, and by the mingling of this form of the protoplasm 

 with the protoplasm of the endosarc, the being is capable of like 

 impulses over its whole formation. But the attributes of eacli, 

 though each is in mingling community with the other, remain 

 distinct, for the endosarc, with its nucleus, decidedly exemplifies 

 attributes which the ectosarc does not possess. It is essentially 

 the digestive and assimilative organ, and the centre of the repro- 

 ductive powers. Its appearances and development vary in dif- 

 ferent kinds, as in endo-divisa, and in some marine forms it is very 

 glassy and never shows diatom remains within it, and the ecto- 

 sarc derives its nourishment from it, "although the latter is the 

 selective agent for procuring and conveying the food. Diatoms 

 and other visible food are never long retained by the ectosarc, but 

 are at once passed into the cential denser endosarc, among the 

 granules located there, implying that there the digestive and 

 assimilative powers are strongest. 



The endosarc never acts in a primary manner in the motion of 

 the being, but always moves successional to the ectosarc, which has 

 centralized in its plasma the whole of the attributes of motion as 

 far as they are evinced in Amoebas. 



