244 Hazen: Lire HISTORY oF SPHAERELLA LACUSTRIS 
INDEX 
PAGE 
Introductory ...........eeeeeiee seen nnnm hene heeeenenennn enhn seerearereren 211 
aPC SCPOXdDE ooh N OT A EIAS c EvetsTe ed oc E e Ete ahedeeetdvs cue 212 
Habitat and distribution 214 
'The resting condition 216 
R eproduction : 217 
'The formation of megazooids 217 
The first g siia p Me qM pe eM M abieavers 217 
: The later generations 220 
Vegetative division 220 
The formation of microzooids. 223 
The so-called conjugation of megazooids 225 
The alleged amoeboid condition. 226 
Special morphology of megazoids................ 226 
The cell-wall and sheaths of cilia....... 226 
The radial strands of protoplasm 227 
The chromatophore and pyrenoids 227 
A contractile vacuole not present 229 
The coloring matters » 229 
Function of the haematochrom $36 
Irritability of zooids 233 
Conditions affecting vitality. 234 
Relation to Sphaerella nivalis to S. lacustris 235 
Nomenclature 23 " 
Synonymy 238 
Summary 239 
Literature. 241 
Description of plates 
