THE TRANSLOCATION OF PROTOPLASM 115 



seen streaming either slowly or rapidly, in one direction only, 

 from cell to cell. 



The hyphae shown at B in Fig. 63, in which protoplasmic 

 streaming was observed, were drawn with the camera-lucida and 

 they have been represented in longitudinal median section. It will 

 be seen that the cells are highly vacuolated. The vacuoles all have 

 one wall adjoining the cell-wall and the other bulging forward into 

 the cell-lumen and, at a bend in a cell, they are usually against the 

 wall on the convex side. Probably one-half of the volume of each 

 cell-lumen is occupied by vacuoles. The cytoplasm in each cell is 

 decidedly granular, and it is the movement of the granules which 

 attracts the eye and enables it to perceive the translocation of the 

 protoplasm from cell to cell. Were the cytoplasm very homo- 

 geneous, as it is in the hyphae of Coprinus sterquilinus, protoplasmic 

 streaming might be in rapid progress, but one would see nothing 

 of it. The direction of the movement of the protoplasm is indicated 

 by the arrows. 



The translocation of protoplasm from cell to cell in the hyphae 

 shown at B in Fig. 63 was watched for six and a half hours. During 

 this time the vacuoles remained without any appreciable change in 

 size. As indicated by the arrows, two streams of protoplasm from 

 two different hyphae met and joined to form a single stream which 

 poured through a third hypha. In another hypha shown on the 

 left of B in Fig. 63, as might be inferred from the absence of arrows, 

 no streaming could be seen. 



Altogether in the hyphae shown at B in Fig. 63 five septa are 

 included and in each of these a median pore has been represented. 



Fig. 62. — Pyronema conflue>i$. Development of the mycelium and formation of 

 vacuoles. Culture medium, a hanging drop of cleared dung-agar. A : ripe 

 spores just sown. B : four and a half hours later ; spores which have swollen 

 up and are putting out germ-tubes ; small rounded vacuoles have been formed 

 in the protoplasm. C : 15 hours after sowing the spores ; the mycelium, 

 developed from the spore a, already has many branches and is septate ; the 

 younger hyphae are full of protoplasm ; small vacuoles have been formed in 

 all the older cells. D : the middle part of an older mycelium ; the vacuoles 

 in the spore and adjacent hyphae are now much enlarged. E-H, enlargement of 

 vacuoles in older cells or hyphae which have ceased to grow ; E, younger cells 

 shortly after their formation, the vacuoles are very small ; F, a hypha which 

 has ceased to grow, its vacuoles are enlarging ; G, older cells, with much 

 enlarged vacuoles ; H, older cells which have very large vacuoles and have 

 lost most of their protoplasm. Magnification, 300. 



