INTRODUCTION TO CRYPTOGAMIC BOTANY 



155 



collections, which requii'es especial notice, as it is the only instance 

 I know, in this group, of the peculiar structure which it exhibits. 

 The threads at first are like those of an ordinary Tyndaridea, 

 but after a time little swellings occur on their sides in which a 

 distinct endochrome is formed, extending backwards into the 

 parent endochrome, separated from it by a well-defined mem- 

 brane, and producing either by repeated pullulation a com- 

 pound mass like that of Calothrix, or simply giving rise to a 

 forked thread. In the latter case there is no external swelling, 

 but a lateral endochrome is formed, which, as it grows, makes 



Fig. 40. 



Threads of Cladozygia Thomsoni, Berk, iu various stages of growth, 

 magnified. 



its way through an aperture whose sides are regularly inflected. 

 I have given to this curious production the name of Clado- 

 zygia Thomsoni. 



10. BuLBOCHiETEiE, Bevh 



Threads articulate, branched, fertile branchlets, bulb-shaped, 



* An appearance is figured in Cladophora fracta, by Kutzing, Phy- 

 cologia, tab. 11, fig. 5, which is of the same natiire ; and souietliiug ap- 

 proaching it in CEdoffonium capillare, ]. c. tab. 12, fig. 2, i., where the 

 lateral branch sends a root down into the parent endochrome. 



