746 



THE A M ERIC AX XA TURALIST. \\\ , r.. XX X\- 1 1 1 . 



ate cells show some dehnitc activity resultini;- in extensive -rowth 

 or peculiarity ot form. Thus some laticifeious cenocvtes are 

 bianchin<; tubes that grow for considerable clisiauces -unoiv the 

 cells ol the tissues in which they are contained The embrvo- 

 sac and the female gametophytes of Selai^inella and Iscx-tes in 

 thcLuK sti^Lsot then de\ elopn-ient aie mteiestm^^ camx \ tcs 



, Ihcli.KlK^vnn Cladophoia) ^^hose cells picscnt^xci) httk 

 chm^c uith i^c except an inciease in si/e \ et vmie ot these 

 conditions, especidl) those illusttated m the Cladophoiacea , aie 

 probably related to the higher types of ccenocvtes 



1 he best differentiated ccenocytes are found in the Si{)hon- 

 ales, Mucorales, Saprolegnialc s and to a lessci extent among the 

 Peronosporalcsand aieespccialh ^^ell illustiated in a leu aquatic 

 forms, such as Monoblepharis and Mvrioblepharis The pecul 

 iant.es of these forms he in elaboiate stiuctuies uhich icsult 

 irom the ability of the coenocyte to respond to several directive 

 stimuli m its growth. The most complicated responses and con- 

 sequently the most highly differentiated morphology is shown 

 among the Siphonales, where some very elaborate forms are 

 found. In many types the plant body is clearly composed of 

 root and shoot regions and in the highest expressions (r. 

 some si)ecies of Caulerpa) there are rhizoids, shoots and leaf- 

 ue structures presenting a remarkable degree of specialization, 

 ihe behavior ot the prot(.plasm in these most highlv differenti- 

 ated tvo... the Siphonales is known to us chiefly through 

 and Klemm. 



studies 

 'I'hc 



changes its p,)sitioi 

 ; *>f tiic plant stre; 

 11 situated in the gr 

 P"-Mtions with its ir 

 •■"loi-ing the cell wal 



l^lasm next t( 

 nbrane (haut 



old wall, thus 

 le called this 



