481 



quite familiar to all observers, and it will be remembered that 

 I noted their occurrence in the second division of theHistolytic 

 Scale. I have in some instances witnessed the abundant de- 

 velopment of monads and vibrios as early as the second day, 

 and under certain circumstances they exist in parts still in con- 

 nexion with the living organism. As the investigation of these 

 living forms did not appear to come directly within the scope 

 of my researches, I took no further notice of them than briefly 

 to assign them their proper place on the scale. In prosecuting 

 further researches, however, I have observed, what no doubt 

 ought to have presented itself to my mind in the first instance, 

 namely, that these animalcules become an element of com- 

 plexity, and also of great additional interest in the study of 

 the general process of Histolysis, not, as might be supposed, 

 from the possibility of their being confounded with the debris 

 of the tissues under investigation, but from the fact that being 

 themselves subject to the all-pervading law of mortality, when 

 they have sported their hour on the stage they in their turn 

 die, and then undergo putrefactive changes, and mingle their 

 remains with the other decaying elements around them. I 

 have also observed the occurrence of certain microscopic forms 

 of vegetation ; protophy ta of the simplest kind, such as very 

 minute cells both isolated and aggregated, vegetable filaments, 

 and certain algal forms, being developed in considerable quan- 

 tities. Under favourable conditions of light I have been ena- 

 bled in almost all instances to detect a faint greenish colour 

 in all these vegetable forms ; with sulphuric acid, and a solu- 

 tion of iodine in iodide of potassium, they usually assume a 

 yellowish tinge, their internal appearances become much more 

 readily seen, and they are themselves distinguishable with 

 great facility from the surrounding elements. At a further 

 stage it is probable these vegetable elements likewise undergo 

 decay. 



" These observations add a new interest to the study of 

 Histolysis, and also throw light on some points on which I was 



