THE TRANSLOCATION OF PROTOPLASM 117 



While the pore itself could not be directly seen, its width — about 

 1 [i — was inferred from the width of the cone of protoplasm seen 

 moving toward it or away from it. These cones, which were studied 

 with a high magnification of the microscope (about 1000, dry 

 system), are shown on a small scale at g, h, and j in Fig. 63, B, and 

 on a much larger scale in Figs. 64 and 67 (pp. 118 and 131). 



The streaming of the protoplasm through the hyphae shown at B 

 in Fig. 63 was rapid when first observed and during the next three 

 hours, but after six and a half hours its speed had declined con- 

 siderably. The flow was continuous, without any halt, and always 

 in one and the same direction. 



As one watches hyphae like those represented at B in Fig. 63, 

 one soon realises that a very considerable amount of protoplasm is 

 flowing through the cells, an amount which must be many times the 

 volume of the cells under observation. Whence comes so much 



Fig. 63. — Pyronema co?ifluens. Translocation of protoplasm along the hyphae in 

 an older mycelium in a hanging drop of cleared dung-agar. Hyphae all drawn 

 with the earner a-lucida. The arrows everywhere indicate the direction of the 

 flow of the protoplasm. 



In general, the protoplasm is flowing : (1) slowly out of numerous hyphae 

 which have ceased to grow, like that at A ; (2) then rapidly through certain 

 mature stable hyphae, like those at B ; then less and less rapidly through 

 younger and younger branched hyphae, like those of which parts are shown at 

 C and D ; and finally, very slowly into numerous rapidly elongating hyphae, 

 like that at E. 



A : protoplasm streaming slowly out of a hypha which has ceased to grow 

 and has become much exhausted. B : part of a mycelium, 38 hours after 

 sowing the spore from which it was derived, consisting of branched septate 

 hyphae containing granular protoplasm p and large fixed persistent vacuoles v 

 attached to the cell-walls ; as indicated by the arrows, a stream of protoplasm 

 is flowing through the hyphae a a and b b and is uniting with another stream 

 which is flowing in an opposite direction through the hypha d d d, and the single 

 stream thus being compounded is flowing through the hypha c c. In the 

 hypha e e the protoplasm, at the moment, is at rest. The five septa, f-j, each 

 have a single small central open pore and through the pores of the septa g, k, i, 

 and j the stream of protoplasm is freely passing. Owing to the conformation 

 of the vacuoles at the ends of the cells by the septa, the moving protoplasm in 

 approaching and in leaving a pore tends to have the form of a cone with the 

 apex directed toward the pore. Examples of such afferent and efferent cones 

 of protoplasm are more or less well displayed in connexion with the pores of 

 the septa g, h, and j. Some highly refractive colourless oval particles are 

 present on the walls of most of the vacuoles abutting on the septa, e.g. at 

 /, g, h, and j, and also here and there on the walls of vacuoles at some distance 

 from the septa, e.g. between the septa g and j, between the septa h and i, and in 

 the hypha a a a little way above the fork. C : cells in a younger hypha, in 

 which the vacuoles are enlarging and through which protoplasm is streaming 

 slowly and acropetally. D : cells in a still younger hypha in which the vacuoles 

 are as yet very small and through which protoplasm is streaming very slowly 

 and acropetally. E : one of many young rapidly elongating hyphae in which 

 protoplasm is flowing very slowly. Magnification, 933. 



