THE TRANSLOCATION OF PROTOPLASM 119 



hypha c c was more rapid than either of the two streams which com- 

 bined to form it. When one traces a main stream forward, one finds 

 that it is flowing toward a part of the mycelium which is branching 

 and re-branching and has ultimate hyphae that are rapidly elongat- 

 ing. With the division and subdivision of the main stream, the 

 protoplasm flows more and more slowly. In cells which are several 

 cells back from a growing point and are still enlarging their vacuoles, 

 like those at C in Fig. 63, the forward flow of the protoplasm could 

 be readily observed ; in very young cells, which are only two or 

 three cells back from a growing point and as yet have very tiny 

 vacuoles, the forward flow of protoplasm could be observed, but 

 with difficulty, while in terminal cells with growing points, like that 

 shown at E, the extremely slow forward movement past the last- 

 formed septum could be detected with certainty only by watching 

 the granular particles of the protoplasm as sharply as possible. 



Streaming of Protoplasm from One Mycelium to Another. — Four 

 spores which had been shot up into a drop of cleared dung-agar on 

 one side of the drop germinated, and each spore gave rise to a 

 mycelium. The four simple mycelia, by means of three hyphal 

 fusions, soon became united to form a compound mycelium. Forty 

 hours after the spores had germinated, protoplasm was observed to 

 be flowing in a main channel of cells made up of parts of the four 

 mycelia, including the four spores and the three fusion passage-ways, 

 away from the side of the drop where the four spores had germinated 

 and the hyphae had ceased to grow, across the drop to the other side 

 and, finally, into a system of hyphae that were at the periphery of 

 the drop and were branching, re-branching, and growing rapidly 

 in length. Part of the main channel of flow is illustrated in Fig. 65. 

 As indicated there by the series of short arrows, the protoplasm was 

 flowing in a dense stream, interrupted by but few fixed vacuoles, 

 along the hypha d, through the spore 6, through the fusion passage- 

 way c, through the spore a, and along the hypha e. This main 

 stream was being fed by numerous tributary streams, of which 

 those in the hyphae/ and g were two. Streaming through the main 

 channel was observed in 161 successive cells. The average length 

 of these cells was at least 0-1 mm. ; so that a simple calculation 

 shows that the length of the main stream, as far as it was observed, 



