1900] CHANGE OF FORM IN GREEN ALG 313 
mwosporangium. Perhaps this fact is attributable to the increased 
general activity in weak solutions. It has no relation to the 
form of the cell, since zoospores are produced from both 
spherical and cylindrical cells, as well as from those of inter- 
mediate shape. 
My approximations to the pressure limits for the different 
fesponses are given in table V. The numbers are all coefficients 
of VX 10-4, 
TABLE V. 
Maximum | Maximum | Minimum | Minimum | Maximum | Maximum 8 
limit to free limit to limit to free limit to limit to free limit to any SS ee 
production production | production | production | production ing 9-1 ge : 
of filaments of any long | of palmella | of any pal- o to} 
filaments orm melloid cells) zoospores | zoospores | zoospores 
PPM ee 
Maxim 
limit to 
— 
Tom 
ig <g 2892 2892 964 964 1928 964 
flaments| 193 482 1928 482 1928 2892 193 
ee 
From table V it will be observed that with the exception of 
the limits for zoospore production, all are much higher for the 
Palmella form than for the filamentous. Perhaps the palmella 
cells become attuned to conditions of high pressure, so that after 
they have existed under these conditions for some time they are 
i nabled to form filaments, and maintain them, at a higher pressure 
_ “0 Was possible previously. Buffum and Slosson (loc. cit., 3 
ae that there was a continual increase in the salt content of 
ote which were imbibing water from a salt solution. Thus the 
___ “ence between internal and external pressures in the case of 
de being Sradually decreased, and this means that the fee 
wally “ate pressure in retarding absorption of water 1S en 
 Wema aan also. Now if this be true in these — ae: 
Siti Y ave in it an explanation of the fact that the paime 
(alway S Srowing in concentrated solutions) becomes to a 
— on less extent attuned to the effects of high arn 6G 
Palme! internal to external pressure may be nearer umity . 
“the. wd cell than for a filamentous one. That the nature © 
__~ Protoplasm itself is changed by prolonged subjection to the 
