130 



the middle of the cell a body staining in hfemaluni is visible, probably a pyre- 

 noid. The branches are given oft" at a certain distance from the acroscopic trans- 

 verse wall, sometimes from the middle of the cell or even, though rarely, a little 

 under the middle. All the vegetative branches are given off in a plane parallel to 

 the surface of the host, while the extremely short fertile branchlets break through 

 the cuticle in a direction perpendicular to that plane. These branchlets consist of 

 a short partly immersed stalk-cell and an entirely free sporangium, but sporangia 

 arising directly from the endophytic filaments also occur. In the fertile part of the 

 plant a sporangium is usually given otT from each cell in the endophytic filament 

 (fig. 55 A). After the evacuation a new sporangium may be formed within the 

 empty sporangial wall, but it may also occur that a new lateral sporangium is 

 given off from the stalk cell besides the emptied terminal one. 



The species appears to be nearly related to Acrochcetium endophyticiim Batters 

 (Journ. of Botany Vol. 34 1896 p. 38B) living in "the cortical layer" of Heterosiphonia 

 coccinea. As far as can be seen from Batters' description this species is distin- 

 guished from Ch. emergens mainly by longer erect filaments, which are composed 

 of from one to three cells. 



Locality. Slv: Mellegrund ofl' Hirslials (XO), 11,5 to l.~) meter.s, with ripe sporangia in August. 



21. ('hantraiisia imniersa sp. nov. 



Thallus endophylicus; fila oinnino immersa, iutercellularia , varie ramosa, 

 ramis sparsis vet ex una cellula pluribus egredientibus. Cellulae nunc cylindricse 

 plerumque tamen medio vel supra medium inflatje, 8 — 10 u lata?, 40 — 53 /j. longse, 

 nunc, praecipue superficiem hospitis versus, breviores plus minus rotundatae, usque 

 ad 15 fj. lata\ (^hroniatophorum unicum stellare pyrenoide centrali et ramis longis 

 sursum et deorsum protractis munitum. Cellulse ultimae breves obovatae vel ro- 

 tundatce, in superficie hospitis prorumpunt, cellulas periphericas illius plerumque 

 non superantes, nonnunquam pilum hyalinum gerentes. Sporangia, transformatione 

 cellularum ultimarum orta, obovata, 15 — 17,5 w longa, 11 — 12 « lata, monospora, 

 post evacuationem saepe sporangio novo e cellula suffultoria formato repleta. 



This species occurs in Rhodomela subfusca and in species of Polijsiphonia. As 

 the endophytes are essentially identical in structure, they are referred to the same 

 species, but as their behaviour to the ditTerent hosts is somewhat different, two 

 forms may be distinguished. 



Forma Rhodomekr. In Rhodomela I have only found the endophyte growing 

 in tumours and occurring in fairly great quantity at Frederikshavn in July 1895 

 and 1896. These tumours are irregularly roundish and somewhat remind one in 

 form and size of Harveyella mirabilis. I conclude that they are occasioned by this 

 endophyte, but it deserves notice that these tumours also contained an endophytic 

 Ectocarpiis or Streblonema and the very common endophyte Bolbocoleon piliferum. 

 The Chantransia grows intercellularly through the whole tumour, the filaments 

 running mainly in a radial direction. The swellings have essentially the same 



