170 TJiANSACTIONS AND PUOCEKDINGS OF THE [Sess. Lxvi. 



point, bound u{) with tlie two-phased process of metabolism 

 in which, while anabolism and katabolism are coexistent 

 and mutually adjusted, it is generally possible, at any 

 given instant, to say, with regard to most tissues, whether 

 anabolism or katabolism is the predominating or charac- 

 teristic phase. There would, then, be a functional inertia 

 of katabolism (or katabolic inertia), a tendency for that 

 phase pre-eminently to be continued after the reception of 

 a stimulus tending to induce any other metabolic distribu- 

 tion (anabolism either equal to or greater than katabolism), 

 and conversely, there would be a functional inertia of 

 anabolism (or anabolic inertia), the tendency for that 

 phase pre-eminently to be continued in spite of a stimulus 

 of opposite nature. This power of maintaining the status 

 quo ante of a particular phase of metabolism, I call the 

 functional inertia of the protoplasm. As examples of 

 katabolic inertia, there is that large class embracing all 

 cases of local life, of organs, tissues or cells, after somatic 

 death, the j^ost-mortem expression of the functional inertia 

 of katabolism, e.g. the muscle of the familiar " nerve 

 muscle preparation," which still " acts " though removed 

 from its nutrient lymph, the excised and isolated bloodless 

 frog-heart beating on a glass plate for hours after the 

 death of the animal, the isolated medullated nerves still 

 giving evidence of conductivity for many hours after 

 excision, the vivisected, non-nucleated portion of Lacry- 

 maria olorl and other Protista, the ciliated epithelium from 

 frog's gullet living for days as an isolated patch, and even 

 the isolated cilium itself exhibiting movements " till it 

 perishes." In this class I do not include the cases of 

 organs surviving by reason of perfused defibrinated blood, 

 for here their metabolism is being constantly supported by 

 nourishment applied under artificial conditions ; but I 

 would include all cases of organs isolated from all nervous 

 and vascular connections, and surviving by reason of the 

 perfusion of salt solution. No food is thereby introduced, 

 the NaCl is powerless to prolong life indefinitely — no 

 longer than the time when the katabolic inertia of the 

 protoplasm shall have been spent. Of course organs and 

 tissues still in situ in the dead body can exhibit their 

 ^ Verworn. "General Physiology." London, 1899, p. 670. 



