THE TRANSLOCATION OF PROTOPLASM 



109 



particular vacuoles. In one cell which was 0-09 mm. long, vacuoles 

 passed from one end of the cell to the other in 9 seconds, i.e. at the 

 rate of 10 p per second or 3 -6 cm. per hour. A lateral hypha came 

 off at an angle of about 45° from its parent hypha and was straight 

 up to a sharp bend. This first straight part of the lateral hypha 

 included two septa and was 0-115 mm. long. Vacuoles traversed 

 this distance in 7 seconds, i.e. at the rate of 16-5 yu per second, or 

 1 mm. per minute, or 6 cm. per hour. This speed may well have 

 been exceeded in other hyphae. 



Data for the rate of flow of protoplasm through hyphae of four 

 species of fungi, of which two are Ascomycetes and two Phycomy- 

 cetes, are embodied in the accompanying Table. 



An examination of the Table enables us to conclude that the 

 rate of flow of protoplasm in the septate and relatively thin hyphae 

 of Fimetaria fimicola and Ascophanus carneus, at ordinary room 

 temperatures, is about the same as that in the non-septate and 

 relatively thick hyphae of Phycomyces nitens and Rhizopus nigricans. 

 This fact suggests that the septa of the mycelium of the two 

 ascomycetous fungi offer but little resistance to the flow of protoplasm 

 from cell to cell, and that the protoplasm must pour through the 

 open septal pores with great ease. 



1 C. Ternetz, loc. cit., p. 284. 2 A. Schroter, loc. cit., p. 9. 



3 J. C. Arthur, loc. cit., p. 495. 



