252 Merkel Henry Jacobs 



with a phenomenon under the control of the nervous system. We 

 have to distinguish, therefore, between metabolic processes, which 

 continue as long as any water is present, and other life processes 

 which come to a sudden stop at the very onset of desiccation. 



This brings up the question, so often discussed in past years, as to 

 whether a rotifer which has been dried as thoroughlyas possible may 

 be said to be living or what Preyer terms anabiotic, that is, lifeless 

 but capable of life as opposed to hfeless and incapable of Hfe. 

 The truth probably hes between the two extremes. We have no 

 reason to believe that there is a complete cessation of all metabolic 

 changes, as Preyer and others have asserted, since so long as any 

 traces of water are present such changes are possible even though 

 they may be greatly reduced in extent, and it is well known that 

 it is impossible to remove all of the free water from organic sub- 

 stances at ordinary temperatures. On the other hand, there 

 appears to be a complete suspension of many of the normal vital 

 processes. Those which depend on movements, either muscular 

 or ciliary, are clearly impossible, and in all probability many others 

 whose nature is more obscure cannot continue in the almost com- 

 plete absence of water. In a dried rotifer, therefore, we have a 

 cessation of the functions of many of the organs as such, while 

 a certain amount of metabolic change in the tissues of the body 

 as a whole still continues. Whether an animal in such a state is 

 to be called hving or lifeless depends entirely on our definition of 

 "life." 



5 Effect of Desiccation on Egg Production 



During the course of the experiments carried on on Philodina 

 it became apparent that a definite relation exists between the 

 periods of drying and those of egg production. It was noticed 

 that at certain times eggs and egg containing individuals were very 

 numerous and that at other times they were almost lacking. In- 

 stead of a continual production of eggs as might be expected in a 

 culture containing individuals of all ages and all degrees of matur- 

 ity it was found that the eggs were produced at almost the same 

 time by all the members of the community regardless of their size 

 and age. On examining the records kept of the condition of the 



