ORGANIZATION AND GROWTH 225 



about 200 per cent., is added to the sea-water, a remarkable 

 phenomenon occurs: large pieces of protoplasm escape 

 from the Tubularise without losing their form. They are 

 surrounded by a transparent membrane which is formed per- 

 haps through their contact with the sea-water. I saw a 

 piece 1-2 cm. long escape from a Tubularian in this way. 



4. That an increased absorption of water by the tissues 

 favors regeneration when it does not exceed a slight amount ; 

 while a greater absorption is harmful, might seem contradic- 

 tory. But it is an entirely general and well-known fact that 

 when water enters cells in too large quantities it acts as a 

 poison. Hoppe-Seyler, for instance, attributes the death of 

 frozen plants which are thawed out too rapidly to the fact 

 that "in freezing, the water separates to a large extent from 

 the solids and collects in crystals. When thawed out rap- 

 idly, the particles of solid matter lying nearest these crystals 

 are flooded with water." 1 



5. The pieces regenerating in the highly dilute solutions 

 often show changes which indicate the great turgidity of 

 the tissues, in consequence of the abnormally great absorp- 

 tion of water. Before the polyp is formed, globular excres- 

 cences appear at the cut ends, and the new polyps are thicker 

 and much more nearly globular than the normal polyps. 

 The opposite phenomena are noted in the strongly concen- 

 trated salt solutions, in which polyps remain exceedingly 

 small. 



6. In conclusion I wish to give a few figures on the rela- 

 tion between regeneration and the absorption of water. In 

 order not to repeat what has already been said, I shall take the 

 figures from experiments in which the concentration of 

 the sea-water was increased by the addition of sodium 

 chloride, or decreased by the addition of fresh water (Serino 

 water). According to Forchhammer, the amount of salt 



1 HOPPE-SEYLEK, Physiologische Chemie (Berlin, 1877), p. 30. 



