550 
(1894) and myself (1898). They are very common in the Danish waters in spring. 
The branches of the nemathecia-bearing plants usually terminate in a globular 
swelling, and the nemathecia arise on the surface of these swellings. Nothing has 
been found to support the supposition of a genetical relation between the inter- 
cellular conducting tissue and the nemathecia, for the said tissue is only to be 
found at a certain distance below the young nemathecia. These arise by simultane- 
ous division of the peripheral cells on a long stretch by periclinal walls, with the result 
that the surface on the stretch in question is covered with close anticlinal cell-rows 
(fig. 531, Plate VIII, fig. 9). The cells of these rows are rounded oblong or ellips- 
oidie and have an abundant plas- 
matic content; the thin plasmatic 
threads connecting the cells of the 
filaments are often easily visible 
in the young stages (fig. 536 D), 
later they could not be observed, 
and the regular arrangement of 
the cells is usually disturbed in 
the microtomized sections owing 
to the swelling of the intercellular 
substance. 
The nemathecia have often 
a limited extent, but two or more 
young nemathecia may fuse to- 
SS 
Ceratocolax Hartzii. ee cats filaments. 4,nuclei gether; the best developed ones 
in the resting stage, ROSE ET, April and May. C—D, nuclei form globular bodies at the end 
in the first division. E, sporangia two- or four-parted. F, sporangia 
four-parted. 625 : 1. of the branches about */2 mm in 
diameter (fig. 530 A, 531). In such 
cases the nemathecium occupies only the outer portion of the globular body while 
the central part is a parenchymatous tissue identical with the medullary tissue 
of the branches. 
The last one or two cells of the nemathecial cell-rows are sterile, the others 
develop into sporangia. The number of the fertile cells in the cell-rows is usually 
only 6 or 7. Fig. 536 A shows young sporangia with nuclei in the resting stage, but, 
without distinct chromatophores. Nor could the latter organs be distinguished in 
the later stages, perhaps with the exception of fig. 536 B where some of the seriate 
small bodies may possibly be reduced chromatophores. The dividing nucleus is 
lengthened with pointed ends, often curved and eccentric, sometimes of the same 
length as the cell. I regret that I was not able to observe the chromosomes in 
material treated with Flemming’s weaker solution or with formalin-sublimate. The 
spindle-shaped bodies were often found divided in the middle, but the following divi- 
sions were not observed, so that it was not decided whether the next nuclear divisions 
take place before the first cell-division. At any rate, the sporangial cell is first divided 
