34 H^EMATOCOCCUS LESS. 



Thus the ciliary movement of Haematococcus, like the 

 amoeboid movement of Amoeba, is a phenomenon of con- 

 tractility. Imagine an Amoeba to draw in all its pseudo- 

 pods but two, and to protrude these two until they became 

 mere threads ; imagine further these threads to contract 

 regularly and rapidly instead of irregularly and slowly ; the 

 result would be the substitution of pseudopods by flagella, 

 i.e., of temporary slow-moving processes of protoplasm 

 by permanent rapidly-moving ones. 



To put the matter in another way : in Amceba the 

 function of contractility is performed by the whole organism ; 

 in Haematococcus it is discharged by a small part only, viz., 

 the flagella, the rest of the protoplasm being incapable of 

 movement. We have therefore in Haematococcus a dif- 

 ferentiation .of structure accompanied by a differentiation of 

 function or division of physiological labour. 



The expression "division of physiological labour" was 

 invented by the great French physiologist, Henri Milne- 

 Edwards, to express the fact that a sort of rough correspond- 

 ence exists between lowly and highly organized animals 

 and plants on the one hand, and lowly and highly organized 

 human societies on the other. In primitive communities 

 there is little or no division of labour : every man is his 

 own butcher, baker, soldier, doctor, &c., there is no distinc- 

 tion between " classes " and " masses," and each individual 

 is to a great extent independent of all the rest. Whereas in 

 complex civilized communities society is differentiated into 

 politicians, soldiers, professional men, mechanics, labourers, 

 and so on, each class being to a great extent dependent on 

 every other. This comparison of an advanced society with 

 a high organism is at least as old as JEsop, who gives 

 expression to it in the well-known fable of " the Belly and 

 Members." 



