no RESEARCHES ON FUNGI 



In Fimetaria fimicola, since a hypha with cells and septa 7-8 /x 

 in diameter has septal pores only about 1-0-1-2 fi in diameter 

 (cf. Fig. 60), it is clear that the area of a cross-section of a cell-lumen 

 greatly exceeds the area of the open space of a pore and that, when 

 streaming is very active and the vacuoles are in motion, the rate 

 of flow of the individual protoplasmic granules must be far more 

 rapid through the pores than through the cell-lumina. 



General Direction of the Protoplasmic Current. — The general 

 direction of flow of the protoplasm in the mycelium of Fimetaria 

 fimicola is in one direction only, without any reversal, from older 

 hyphae which have ceased to grow toward rapidly growing younger 

 hyphae. There can be no doubt that this translocation serves to 

 aid the younger hyphae in their growth. 



A reversal in the direction of flow of protoplasm in any particular 

 hypha, although not actually observed, must often take place ; 

 for, when a hypha is growing rapidly in length, protoplasm may 

 flow into it from older hyphae which have ceased to grow but, if 

 the hypha should cease to grow, its protoplasm may flow out 

 of it into younger rapidly growing hyphae situated in another 

 part of the mycelium. Doubtless, also, a reversal in the direction 

 of flow in a particular hypha is sometimes brought about by 

 changes in pressure suddenly arising from the establishment of 

 a new anastomosis between two or more mycelia or systems of 

 hyphae. 



Gelasinospora tetrasperma. — Gelasinospora tetrasperma, like 

 Fimetaria fimicola, is a coprophilous Pyrenomycete, but it differs 

 from F. fimicola in having four spores in each ascus instead of eight 

 and in having its spore- walls pitted instead of smooth. It was 

 isolated by Dr. Dowding from ptarmigan dung collected in northern 

 Manitoba and will shortly be described by her under the name 

 here given. 1 



Hanging drops of malt-agar were inoculated with the mycelium 

 of Gelasinospora tetrasperma. The mycelium grew rapidly in the 

 drop and, within 24 hours, exhibited protoplasmic streaming. 

 In hyphae in which the streaming was slow the vacuoles remained 



1 Eleanor S. Dowding, " Gelasinospora, a New Genus of Pyrenomycetes with 

 Pitted Spores," Canadian Journal of Research, Vol. VII, 1933. 



