CHAPTER II 



EFFECT OF VARYING MOISTURE UPON PROTOPLASM 



IN this chapter it is proposed to speak (I) of the amount of 

 water in organisms ; (II) of the effect of desiccation upon the 

 functions of protoplasm ; (III) of the acclimatization of organ- 

 isms to desiccation, and (IV) of the control of the direction 

 of locomotion by moisture hydrotaxis. 



1. ON THE AMOUNT OF WATER IN ORGANISMS 



Any theory of the structure of protoplasm must recognize 

 that water forms the greater part of the whole mass ; between 

 60% and 90%. In the case of dry seeds and grains, however, it 

 may fall below 15%. Many determinations have been made of 

 the proportion of water in the body of entire organisms and in 

 their organs. I give in tabular form some of these determina- 

 tions, which were made by BEZOLD ('57), designated by (B) ; 

 KRUKENBERG ('80), designated by (K); and LIEBERMANN 

 ('88), designated by (L). 



TABLE VIII 



SPECIES. 



CONDITIONS OF WEIGHING. 



% WATJSU. 



Various sponges (K) 



Medusa : Rhizostoma Cuvieri (K) . 

 Various Actinia (K) 



Alcyonium palmatum (K) .... 

 Asteracanthion glacialis (K). . . 

 Lumbricus complanatus (K) . . . 



In most cases, kept a short time in 

 fresh sea water ; dried on surface 

 and weighed. 



Whole animal, directly from water 



Piece of disc. 



A few minutes after removal from 

 sea. 



A little water lost from central cavity 



Weighed when fresh, 73.5 g. 



Weighed 850 g. 



2 large specimens 



58 



84.0 to 

 74.5 

 95.4 

 95.0 



87.7 to 



83.2 



84.3 



82.3 



87.8 



