THE CRITERIA OF LIVINGNESS 85 



what we have already alluded to as one of the remarkable 

 differences between the organic and the inorganic — Individ- 

 uality. We come back to what was said of old : — '' All flesh 

 is not the same flesh: but there is one kind of flesh of men, 

 another flesh of beasts, another of fishes, and another of 

 birds.'' 



Prof. Charles Richet and other physiologists have of 

 recent years devoted much attention to the phenomenon that 

 dosing an animal with certain poisons may bring about, 

 if the animal survives, a peculiar physiological condition, 

 called anaphylactic, which make the creature hyper-sensitive 

 to subsequent doses. An extract of sea-anemone's tentacles 

 is very poisonous to dogs, but, when the dog recovers, a very 

 minute second dose a month afterwards may be rapidly fatal. 

 The phenomenon of anaphylaxis is extraordinarily subtle; 

 thus a man to whom shrimp flesh is poisonous may be un- 

 affected by lobster. He is violently poisoned if he eats a 

 single shrimp, and yet he is able to enjoy a whole lobster; 

 straining at a gnat, he swallows a camel with ease. The 

 importance of this is that it points towards the conception 

 of the chemical individuality of the living creature. There 

 is a specific chemical constitution which is on the whole 

 best for the species in question, which makes for stability. 

 Those that survive the introduction of a poison, it may be 

 the 'result of digesting a particular kind of food, do not 

 necessarily mark the surviving type, for they may be killed 

 by the anaphylactic violence following a second dose. So 

 much the worse for the individual, but so much the better, 

 possibly, for the species, which cannot safely admit of any 

 compromise with poison. Thus, speaking of man, Richet 

 says : ^^ Anaphylaxis appears to be an eflicacious and ener- 

 getic method of maintaining the chemical stability of our 



