108 HEREDITY. 



happens it that the representatives of no one cell are 

 ever exuded or breathed away in any case ? Gem- 

 mules may go anywhere. But in spite of all the 

 tossings of the tissues, in spite of all the activities of 

 the tissues in organisms that are constantly in mo- 

 tion, we find no one class of these gemmules lost. 

 If, for instance, the gemmules that come from the 

 lenses in the eye were to be perspired away ; or if, 

 as they circulate through the blood, they were to be 

 breathed away, there would be no eye in the off- 

 spring. Now, how is it that there is nothing lost out 

 of this marvellously complex mass of gemmules, when 

 they are so inconceivably minute that hunting for a 

 needle in a haymow is plain business compared with 

 looking for a gemmule ? This is the best form of 

 the mechanical theory of life ; and, in the name of 

 theories as wild as this, some of us are asked to give 

 up our belief in the immortality of the soul. 



3. The hypothesis makes no distinction between 

 a unit of matter and the unit of force in a living 



o 



organism. 



The individual type of life, or co-ordinating power 

 in a germ or organism, I call the unit of force in that 

 germ or organism. A single, naked, bioplasmic mass 

 is the unit of matter. Cells are not the true units of 

 matter in an organism. If the gemmules are formed 

 by the breaking-off of minute masses from the units 

 of matter, or naked bioplasts, these will not arrange 

 themselves unless the unit of force or co-ordinating 

 power of life is behind them. 



It is vastly important, I think, to make a distinc- 



