BY A. JEFFERIS TURNER, M.D. 29 



composed, at least to all appearances, of this living jelly. Sarcode 

 is without visible organs, and has no appearance of cellularity ; 

 but it is nevertheless organised, for it emits various prolongations 

 along which granules pass, and which are alternately extended 

 and retracted ; in one word, it possesses life." In this old 

 description, to which the most recent science has but little to 

 add, you will note the stress laid upon the movements of 

 protoplasm as indicative of life. And, indeed, these movements are 

 sufficiently remarkable. It is true that of recent years Biitschli has 

 shown that if oil be rubbed up with certain alkaline salts in a moist 

 condition, and a minute fragment of the paste be examined in 

 water, the latter diffuses into the paste and converts it into a 

 froth, in which streaming movements occur and changes of 

 external form not unlike those shown by living protoplasm. 

 These movements are due to diffusion currents set up by the 

 chemical changes taking place between the water and the soapy 

 oil. How far they can be regarded as explaining the movements 

 of protoplasm is, I think, very doubtful. Similarity may be 

 apparent as well as real, and it is very doubtful whether 

 protoplasm really consists of a vacuolated mass as Biitschli 

 contends, and further, even more doubtful whether these simple 

 diffusion currents, which cease after a time, really explain in any 

 way true amoeboid movements. 



But there are other and more subtle differences between 

 living and non-living matter. A proper mental grasp of these 

 is essential to the understanding of our problem. They consist 

 in chemical changes which are characteristic. All living matter 

 has this in common, that it continually absorbs oxygen and gives 

 oft" carbonic acid. If you will consider this for a moment, you 

 will see that it involves the recognition of the fact that living 

 protoplasm is always in a state of wasting or decomposition. Its 

 constituent molecules, which consist partly of carbon, are con- 

 tinually becoming oxidised and breaking up into much simpler 

 non-living chemical compounds. As a necessary condition to 

 its existence, it possesses the opposite power of taking up non- 

 living matter and transforming it into protoplasm. Its chemical 

 equilibrium can only be maintained by a continual succession of 

 chemical changes, opposite in character, for its substance is in a 

 continual state of flux. On the one hand is an in-stream of 

 molecules containing carbon, nitrogen, &c. ; on the other, an 

 outflow of the same elements in other, usually much simpler, 



