SOME ENDOPHYTIC ALG.E. 295 
impossible is shown by observations made by Oltmanns and 
others (7. p. 344). Not only endophytes, but also parasites 
have been recorded as developing on glass dishes in artificial 
cultures. 
The question of the infection of Nitophyllum in the spring 
raises some points that cannot yet be explained. So far as is 
known, JV. Hillie is an annual plant, it dies away in the 
winter, and therefore no home can be found for Zadoderma 
in its tissues till the following spring. What becomes of 
the Endoderma spores that are formed in abundance in late 
autumn? Presumably they germinate at once. Other species 
of Nitophyllum do not throw any light on the subject. N. lace- 
ratum, the commonest British species, grows throughout the 
whole year, but it is remarkable for being entirely free from 
Endoderma (see later). It is possible that the spores may infect 
entirely different genera during the winter months, such as 
Ceramium or Delesseria. This can only be verified by carefully 
carried out artificial cultures. 
The growth of Endoderma viride forma Nitophylli, in contrast 
to some other species (e. g. E. gracilis), takes place entirely 
within the substance of the host-plant, and there is no trace 
whatever of external branches or hairs. This character, taken 
together with the occasional production of filaments which run 
along the middle lamella of the inner tissues of the host, points 
to its being most adapted to au eudophytie mode of existence, 
and that it has probably grown longer under such conditions, 
than forms that produce external hairs. 
At the same time, there is no evidence to show that the plant 
is in any way parasitic. The presence of chlorophyll and the 
entire absence of any haustoria-like organs do not suggest it ; 
on the other hand, the cells of the host are perfectly healthy even 
though it be richly infested. In late autumn Endoderma is still 
found flourishing in the tissues of Nitophyllum, but there is no 
reason to suppose that the decay of the fronds is hastened by its 
presence. 
Before coming to the list of plants infected by Endoderma, a 
point in the general morphology may be noticed. The filaments, 
when in the thallus of N. Hillie, are as a rule moderately 
regular in width and general form. Au exception to this occurs, 
however, when the endophyte passes over tissues other than 
