595 
with the fruit” and depicted them as irregularly spherical bodies from which small 
adventitious shoots are given off. 
SCHMITZ gave a more detailed description of the tumours, especially their 
anatomical structure; he showed that the interior 
of the tumours is built up of a medullar tissue 
of interwoven cells whereas the cortex is some- 
what similar to that of the normal plant. In 
the cortex rhizoids may appear, sometimes in 
great numbers. Scumirz further stated that almost 
the whole tissue of the tumours, in particular 
the cortex, is filled with small, nearly oval 
bacteria. The bacteria live intercellularly in 
the middlemost layer of the cell-walls. When 
they are very numerous, they penetrate towards 
the surface of the tumour, numerous rhizoids 
are then produced, the cells are partly disun- 
ited and the bacteria can escape into the sur- 
rounding water. SCHMITZ supposes that the tumours 
are galls occasioned by the bacteria. 
The tumours have recently been examined 
by CHEMIN who confirmed the observations of 
Fig. 598. 
Cystoclonium purpureum. Parts of frond with 
tumours. A, 3:1. 
Fig. 599. 
Cystoclonium purpureum. 
Upper end of shoot with 
hapters and a tumour. 
23:01. 
Schmitz. He states that the bacteria are “légèrement ovoides 
et leur grand axe atteint à peine 1 w’. He mentions an 
attempt at inoculating bacteria from a gall to another indi- 
vidual of Cystoclonium, without result however, but nevertheless 
he agrees with Schmitz in considering the tumours occa- 
sioned by the bacteria; in all the tumours examined he found 
bacteria. 
The tumours from the Danish waters examined by me 
agree with those described by the authors quoted, as to the 
outer appearance and anatomical structure; but there is the 
discrepancy that I have not been able to observe the inter- 
cellular masses of bacteria. In the swollen membranes of 
the tumours, only the homogeneous substance of the middle- 
most layer was to be seen, no bacteria, even after staining 
with gentiana-violet, and this was the case, too, in the large 
tumours with disunited cells. Only scattered rod-shaped bacteria 
much larger than those described by CHEMIN were sometimes 
observed. It seems doubtful, therefore, whether the tumours 
are really caused by bacteria; their etiology must be left for further research. 
* Fr.Scamirz, Knöllchenartige Auswüchse an den Sprossen einiger Florideen. Botanishe Zeitung 1892. 
) 
= E. CHEMIN, Action des Bactéries sur quelques Algues rouges. Bull. de la Soc. bot. de France 1927, p. 441- 
76* 
