William J. Hodgetts. 
found or dredged from deep water in sheltered, moderately 
sheltered, and exposed situations. 
It is possible that when plants are wounded, numerous offshoots 
arise at the point of injury. I have often observed that Fucus 
fronds, where cut, produce tufts of proliferations—a phenomenon 
somewhat akin to the growths described above. This subject 
requires further careful investigation. 
THE CONJUGATION OP ZYGOGONIUiM 
ERICETORUM KUTZ. 
Bv William J. Hodgetts, B.Sc. 
[With Two Figures in the Text.] 
I.-1NTRODUCTION. 
LTHOUGH Zygogonium ericetorum Kiitz. (=Zygnetna erice- 
to rum Hansg.) is such a common alga, occurring either as 
the terrestrial form on heaths and damp peaty ground generally, 
or as the aquatic form in peaty water, yet conjugation must be 
a very rare occurrence with it. Hassall (5) found “union to 
have taken place between some of the filaments of Conferva 
{Zygogonium) ericetorum ,” but states that such a condition is 
“ very rarely met with.” He gave no figure and no details. 
West and Starkey (10), in their study of Z. ericetorum , made 
numerous cultures of it under various conditions, their work 
extending over a long period, but were unable to induce conjuga¬ 
tion ; and they conclude that it “appears very rarely, if ever, to 
conjugate.” West (8) states that Z. ericetorum from this stand¬ 
point is “ on the whole .... the most inert and unresponsive 
alga at present known.” Resting cells (“ cysts ”), akinetes, and 
aplanospores, however, are not at all uncommon with this species, 
and appear to be the chief means by which it tides over unfavour¬ 
able periods. Fritsch (4), for instance, has recently described an 
extreme terrestrial form of Z. ericetorum which may be said to be 
permanently in the akinete condition. 
De Bary (3), in his classical work on the Conjugatae, gave a 
