THE TRANSLOCATION OF PROTOPLASM 89 



and Laminar ia saccharina, the " trumpet hyphae " are true sieve- 

 tubes and the structure of these sieve-tubes resembles that of 

 Phanerogams. In these species she also demonstrated the existence 

 of protoplasmic connecting-threads passing through the closing 

 membranes of pits throughout the tissues. 



It was natural that, after protoplasmic connexions had been 

 found to exist between adjacent cells in Phanerogamia. Pteridophyta, 

 Muscineae, and Algae, they should be looked for in Fungi. The 

 first to notice pits in fungus walls was de Bary, 1 in his well-known 

 Text-book published in 1884, but he gave no indication whether 

 the pits were closed or open. He says: "The thick transverse 

 walls of Dactylium macrosporum Fr. which are formed of two semi- 

 lenticular lamellae have a large pit in their centre, just in the same 

 way as it occurs in the transverse walls of filiform Florideae like 

 Callithamnion. I have never seen pits in other Hyphomycetes ; 

 their transverse walls are usually delicate but often, as in Botrytis 

 cinerea, they appear to be thinner in the middle than at the 

 margin." 



Strasburger, 2 in 1884, in his Practical Botany, described and 

 illustrated pits in the septa of the stipes of Agaricus (=Psalliota) 

 campestris and A. pratensis. 



Chmielewski, 3 in 1886, discovered and described perforations in 

 the septa and protoplasmic connexions between successive cells in 

 the hyphae of Haplotrichum roseum Corda. 



In 1893, Wahrlich, 4 in an important paper, published in both 

 Russian and German, demonstrated that septal pores and proto- 

 plasmic bridges between cells are characteristic of Fungi in general 

 (Figs. 49-52). In making his preparations he used fresh material 

 and fixed it with a watery solution of iodine in potassium iodide, 

 with more iodine than usual, so as to obtain a darker colour in the 



1 A. de Bary, Vergleichende Morphologie und Biologic der Pilze, Leipzig, 1884, 

 p. 14. 



2 E. Strasburger, Das Botanische Practicum, Jena, 1884, pp. 324-325. 



3 Chmielewski, " Zur Morphologie von Haplotrichum roseum (Corda)," Ber. der 

 neuruss. Naturf.-Gesell, Bd. VI, Odessa, 1886 (in Russian). Cited from Wahrlich. 



4 W. Wahrlich, " Zur Anatomie der Zelle bei Pilzen und Fadenalgen," Scripta 

 Botanica Horti Universitatis Imperialis Petropolitanae, T. IV, 1893, pp. 101-155 

 Tab. II-IV. 



