4. 



Iffic i'.iea in such invaetigationa arias aa the result of tmc ohemioel composition 



of aea water and may be largely oli»in*»ted by tha ue« of fraah »*t*r form*. 

 Thua Haas (1916) hsa eho*n that tha addition of hyirotlaa to *** water reaulte 

 in a proportion te increase in OH ion ouncantr»tion only aftor all of tha Ca 

 and Kg have bean precipitated out iu th* form of their basic carbonates. 



This diaoovary is of twofold Importance for it asmna in the flrat 

 place that awch of tMl base added to the eea water la ioRediately thrown 

 out, ar. 1 in tha seoond pl*co, Ihe disturbance of t^e balance between the salts 

 of la, K, Ca and Mg, which Loeb (1903) ha* ah own la exceedingly hnrrcful to 

 marina an ism 1*. 



In working with acids too, the use of ae« water presents certain 

 difficulties, for any strong acid added to aea water will imaediritoly form ealta 

 with tha liberation of COg. Hence no comparison of the effects of th<> various 

 mineral acid* in ?oaaibls,a8 the acidity esisiting in the eea water la due to 

 H2CO3. For theme reason*, end alao to aee whether fresh crater animals are 

 adjusted to a d iff a rant H ion optimum than marine organisms, the author at flrat 

 wlahed to undertake a atudy of the effects of bases end acids upon development 

 and growth of some fresh wster fore. ^inoo, however, there were no eggs or 

 young larvae available at the time of year »h9n this investigation must ba done, 

 it w»e decided to uao regeneration which in many way* resembles original growth. 

 This aeamed further deaimble beesrioe M such studies of regeneration h^ve ae 

 yet been m=»de Mai it is probable thst comparative studies of regeneration and 

 growth under varyinr environmental conditions wight throw much light upon the 

 extent of Mm similarity or dissimilarity of the two proceseee. fhtt la true 

 of tha effects of hydrogen ion concentration is also true of tat affect of oxygen 

 i» regeneration. As yet no experimental studies are kmmtn to tnva been awde 

 on regeneration in varying concent rations of oxygen. As rapid mstaboliam 

 aal rmmil growth re uaually associated, tha meVibollam experimenta were under- 

 taken to aea whether any correlation coal! ba traced between the r*te of 



