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Having regard to the extremely limited powers of locomotion 

 in the Foraminifera, it is obvious that those species which form a 

 shell or covering of adventitious matter, instead of secreting one 

 by chemical processes from the sea-water, can only do so by 

 utilising the material on the spot. Hence it might, perhaps, be 

 thought that there would exist great similarity between different 

 forms living on the same spot and under identical conditions. 

 But such is not the case, for nearly every species has well-marked 

 characteristics which serve to distinguish its test from those of 

 closely allied forms, and nearly all possess some mysterious power 

 of selecting material which leads to the most striking results, and 

 which, when considered in relation to the extremely low organisa- 

 tion of these animals, can only be regarded as wonderful. Thus 

 one form will utilise nothing but large grains of sand, which are- 

 cemented together very roughly and without any attempt at 

 symmetry ; another species utilising grains of the same size will 

 lay them side by side with such neatness as to form a sphere of 

 practically smooth surface ; a third will reject all large grains 

 of sand, and build with nothing but the finest grains ; while yet 

 another, rejecting sand altogether, will utilise the almost impalpable 

 mud, and plaster it over a chitinous membrane as support. Other 

 species show a marked predilection for sponge spicules, which are 

 always present in greater or less abundance in marine muds, and, 

 selecting these, cement them side by side to form a thin shell- wall, 

 or felt them together with tine sand and mud for the same 

 purpose. To grasp fully the significance of such a marvel of 

 construction as is presented by the shell of a Tech nit ella (the 

 term meaning "little workman," and, the lecturer thought, well 

 named), one must remember that the animal which formed it was 

 but a tiny particle of protoplasm with a nucleus, and had no 

 organs of any kind, whether alimentary, muscular, or nervous. 

 Mr. Earland said that when showing such specimens he had often 

 been confronted with the remark, " Oh ! that is nothing very 

 wonderful ; the Caddis larva can do as much as that," or " Meli- 

 certa can build a tube better than that." This, of course, was 

 quite true ; but the Caddis larva and Melicerta are, in organisa- 

 tion and structure, as far above the Foraminifera as man is 

 above them. Knowing their complex structure and organs, we 

 need not admire their work any the less if we admit that the 

 Rhizopod, without organs of any kind, can outbuild them all. 



