"WATEE SILK 57 



i. The structure of the fruiting filament. — Are there any 

 noticeable changes in shape or size as compared 

 with the vegetative filament ? In color % Do the 

 cells have the usual contents ? Can you find 

 the chromatophores, nucleus, etc., in each cell of 

 the fruiting filament ? Is starch present ? 



c. The position of the fruiting filaments. — In what posi- 



tion do the fruiting filaments lie? What deter- 

 mines this position mathematically ? Physiolog- 

 ically ? Do the filaments touch at aU points ? Do 

 you find a filament in any part of its course in 

 contact with more than one other filament ? 



d. The conjugating tubes — How many does each cell 



have ? Do all of the cells have them ? How do 

 they compare in shape and size with the rest of 

 the cell ? Look for tubes in various stages of de- 

 velopment. How are they formed ? Are they a 

 mere " bulging out " of the ceU-wall, or are they 

 true outgrowths of the same? Do they always 

 grow from the same side of the cell? "What is 

 their structure ? Do they show the same struct- 

 ure and composition as the cell-wall ? "What de- 

 termines their place of formation physiologically? 

 Are the filaments actually in contact before the 

 tubes form? Are they open at the outer end 

 from the first stages of formation ? If not, when 

 do they become open? Do the tubes in conju- 

 gating filaments appear to be permanently grown 

 together, or are they only in temporary contact ? 

 "What becomes of the tubes after the zygospore 

 is formed? 



e. The zygospores. — Do they occur in both filaments ? 



