ANABIOSIS OF THE EARTHWORM 71 



Thus, only one difference can be stated in the earthworms as 

 compared with the other groups of anabiotic animals — it is that 

 they are not so amenable to continued preservation in the exsic- 

 cated state at normal temperature. This is evidently accounted 

 for by the more complicated organization of worms and the 

 presence of a more highly organized blood system, as well of a 

 large quantity of microorganisms in the gut. The exsiccation 

 of the skin carried on too far destroys its capillary vessels and 

 causes the blood effusion. The microorganisms of the gut and 

 of the surface of the body, multiplying under favorable con- 

 ditions, bring about the death of the worm. 



While showing a full analogy to the anabiosis of Rotatoria, 

 Tardigrada, and Nematodes, the phenomenon of exsiccation of 

 the worms has the practical advantage of affording the possi- 

 bility of determining the amount of the loss of water contained 

 in the body of the worm. And in this direction I have discovered 

 a fact, which seems to be of great interest : a very large percentage 

 of water can be lost without the complete loss of vitality. 



As my experiments (cf.. series IV, worm no. 1) have evidenced, 

 earthworms can revive and regain the normal state of life after a 

 loss of 61.6 per cent of the weight of the body, or nearly 73 per cent 

 of the weight of the water contained in the body. 



If we take into consideration that the organization of the 

 earthworm is comparatively infinitely more complicated and 

 therefore more delicate than the organization of Rotatoria, 

 Tardigrada and Nematodes, we can readily admit, that these 

 microscopical animalcules may have the capacity to revive after 

 having lost 80 to 85 per cent of the amount of water in their 

 bodies, or perhaps even more. 



This consideration throws some light on the seeming mysteri- 

 ousness of the phenomenon of anabiosis that was discovered 

 more than 200 years ago, but till now no known analogy in the 

 higher groups of the animal kingdom. 



Petrograd, February 1. 1918. 



