12 ELEMENTS OF l)IOLO(}Y. 



therefore, has what in the case of an annual would be spoken 

 of as "organisation." Each part or "organ" of the machine 

 has certain definite functions, and the machine carries out 

 its appointed work, when suppHed with the necessar}^ force, 

 in virtue of the harmonious combination and interaction of 

 its several parts. Most animals, in the same way, consist 

 of definite parts or organs, with fixed relations to one ano- 

 ther, and each discharging its own work or function in the 

 general economy. So far the comparison is a good one, 

 but it may be, and has been, carried too far. It is the very 

 essence of a machine that it should consist of definite parts. 

 It does not matter whether we are dealing with a toasting- 

 fork or a steam-engine, we have in all cases a body com- 

 posed of different parts performing different functions ; and 

 no work can be got out of the machine unless by the invo- 

 cation of a separate factor to supply the necessary force. 

 It has been hastily assumed that the case is the same with 

 animals, and the common simile has gone far to foster and 

 diffuse this belief It has, in fact, been unhesitatingly laid 

 down that life is inseparably connected with organisation; 

 nay, more, it has even been asserted that life is the result of 

 organisation. The falsity of this belief, however, is conclu- 

 sively shown by the study of the minute creatures known as 

 the Foraminifera (fig. i). These little animals possess the 

 power of secreting a very beautiful and elaborate external 

 envelope or shell, and they thus obtain a spurious kind of 

 complexity which is very strikingly at variance with their 

 real simplicity. In point of fact, the bodies of the Foram- 

 inifera exhibit nothing which could truly be termed "organ- 

 isation." They consist simply of formless and structureless 

 albuminous matter. They are not composed of definite 

 parts or organs, and they are in no proper sense to be com- 

 pared to machines. Nevertheless, they live^ assimilate 

 nourishment, grow, maintain their existence against hostile 

 forces, have certain relations with the outer world, and 

 reproduce their like. The highest animal, regarded merely 



