i 4 o RESEARCHES ON FUNGI 



had sent out an intrahyphal hypha which had grown through the 

 dead cell a b c, had united with the living cell p, and had also united 

 with the other intrahyphal hypha at e. Thus in this instance a 

 relatively complicated injury to a hypha, resulting in the death of 

 two cells and the division of the mycelium into three separated 

 living parts, was soon healed and the unity of the mycelium restored. 

 There can be but little doubt that, under natural conditions, 

 owing to the growth movements of Phanerogams and other plants, 

 locomotory and other movements of small animals, etc., the my- 

 celium of such fungi as Pyronema confluens and Fimetaria fimicola 

 must often be injured, so that some of the cells die. Doubtless 

 many of these injuries are healed up by the production of intra- 

 hyphal hyphae and the fusion of these hyphae with one another or 

 with other older cells. Fruit -bodies can be produced only when 

 the mycelium as a living unit has attained a sufficient mass. Any 

 growth reaction, such as the production and fusion of intrahyphal 

 hyphae, which tends to restore the unity of a mycelium which has 

 been accidentally divided into part,-, must therefore tend to promote 

 reproduction and, indirectly, to be of advantage to the fungus 

 species concerned. 



Ascophanus carneus. — As we have seen, streaming in this fungus 

 was discovered and investigated by Charlotte Ternetz in 1900. 



Some tiny reddish fruit -bodies were found on old hay which had 

 been kept for a long time partially immersed in water in the labora- 

 tory, and they were identified by my colleague, Dr. G. R. Bisby, as 

 belonging to Ascophanus carneus. One of the fruit-bodies was cut 

 up, and some pieces of it were put in a hanging drop of cleared 

 dung-agar. Very soon hyphae began to grow from the pieces 

 of fruit-body into the agar and, next day, the mycelium which 

 developed from these hyphae was examined under the microscope. 

 In several of the hyphae protoplasmic streaming was in active 

 progress. In one part of the culture, in a hypha lacking vacuoles, 

 the protoplasm was seen streaming through fourteen cells in suc- 

 cession, away from an older part of the mycelium where vacuoles 

 were developing and toward younger rapidly elongating hyphae. 

 These observations confirm similar ones made by Ternetz. 



A brief study of protoplasmic streaming in the mycelium of 



