131 
structure as the normal branches; there appears to take place only an acceleration 
of the growth, their structure assuming the appearance of that of much older 
branches. In the interior of 
the tumour the cells of the 
endophyte are usually several 
times as long as broad, nearly 
cylindrical; towards the peri- 
phery they become shorter, 
lastly only a little longer than 
broad. At the same time the 
filaments become more bran- 
ched. The outermost cells 
reaching the surface of the host 
bear sometimes a short hair 
ca. 4,5 # thick at the base but 
-@- 
PL aeg ® c E 
Fig. 56. 
Chantransia immersa f. Rhodomele.* A, section of tumour of Rhodomela 
quickly tapering upwards. 
with the endophyte; a new sporangium is about to be formed within 
an emptied sporangial-wall. B and C, ends of filaments with hair. D, 
The structure of the cells filament with sporangia, one emptied. Æ, filament showing the chro- 
matophores. 300: 1. 
was studied on material har- 
dened with picric acid. The pyrenoid is large and contains an angular body, pro- 
bably a crystalloid. It is situated nearly in the middle of the cell but not always 
Fig. 57. 
Chantransia immersa f. Rhodomele. 
Cells showing the chromatophore ; 
hardened with picric acid. A, young 
cells, p, pyrenoid, n, nucleus. B, the 
pyrenoid contains a crystalloid. C, 
the chromatophore with long arms, 
the pyrenoid excentric. A 730:1. B 
580:1. C 1100: 1. 
in the axis of the cell (fig. 57 B, C). The arms of the 
chromatophore are long and narrow and extend from 
the central part containing the pyrenoid upwards and 
downwards to the ends of the cell. The nucleus is 
difficult to see; by aid of borax-carmine it was deter- 
mined in young cells, lying in a pit in the chromato- 
phore near the pyrenoid (fig. 57 A, n). 
The sporangia arise almost without change of form 
from the outermost cells lying at the level of the sur- 
face of the host or a little prominent. After the eva- 
cuation a new sporangium may be formed within the 
emptied wall from the under-lying cell (fig. 56 A). 
Forma Polysiphoniæ. Of this form which has been 
found growing in Polysiphonia nigrescens and P. violacea 
I have particularly examined specimens infesting P. ni- 
grescens collected at Hirsholmene in September. It oc- 
casions here no tumours but grows intercellularly be- 
tween the central cell and the pericentral cells as well 
as between the latter mutually. Long straight filaments 
consisting of cylindrical or feebly swollen cells often run 
longitudinally between the central cell and the pericentral cells, sending off between 
the pericentral cells radiating filaments ending with short cells breaking through 
17° 
