HYBRIDS AMONG SPECIES OF SPIROGYRA^ 



PROFESSOR EDGAR NELSON TRANSEAU 

 Ohio State University 



Conjugation between filaments of different species of 

 Spirogyra have been reported by several students of the 

 alga\ Bess-ev (1884) reported and figured zvaospores 

 formed by the erossin- of S. majusoila and S. pinfn fa. 

 He iK.ted that tlie >pore> fonue.l by the ,to>.^ in cither 

 dirertioii ronv^p.uided to the ^poiv tvpr of Hi., female 

 filament. This has been coniirnie.l by all Mihs,M,uent ob- 

 server.v and we shall see later that tiiis i^ a ne.-e.^.^ary 

 result of the process of fertilization as it (.c.-ui'> in Sj/iro- 

 giira. Thi^ ci.js^ i> .)f particular interc-t bcfauM- the 

 veoftative .-ell. of luajnsmJn have plain end walN. while 

 those of prnfrrfa have replicate end walU. Con^e.iuently 

 th(-re i^ nothino- in the i.hysiolooy of th(-e two >pc.Mes, 

 reprcM'iitative of the two divisions of the uvnu--. that in- 

 terfere^ with conjugation. Wolle (b^SS) Huur.'^ a .-ross 

 between S. uia.nnui and S. / uilifia under the name of 

 S. wurlma var. -n;a <iu,ills. \Ve>t an.l AVeM ( 1S!»S) fiuured 

 a cro» between two of the ^nallei- >i..'cie. ..f .S'/wVor/z/m 

 but .li.l net uive their names. An.lrew^ (imi) ti-ured 

 and .IcM-ribcl a cnvs between N. miss.,. „ne of .mr hir- 

 cst species, with several ch I'omatophoiv^ in ea<-li cell, and 

 S. mnnHiiHis, one of the smallest of our >pe,-i.-. with a 

 sinoio chromatophore. Here again the sp.nv f..rmed re- 

 send)les that normal to the female tilament. Hvi.lently 

 differenees in h/.c. in number of chromato].hon-. ^hape 

 of zygospore, and character of the eml wall^ of tit." vege- 

 tative cells are not impediments to cro>ving. In the col- 

 lections from central Illinois which 1 liaw Mndie.l I have 



