216 COHN’S ‘‘BEITRAGE ZUR BIOLOGIE DER PFLANZEN.” 
fissures or gaps in the surface caused by injury to one or several of the 
superficial cells. In the case of Variolaria communis many Palmella- 
ceous forms entirely similar to the gonidia (as well as other foreign 
: : ; f 
the border of the gonidial layer occur very 
capacity for multiplication ; the two facts taken together would see 
to show that the gonidia have been gradually adapted to their habitat, 
this adaptation having been rendered possible through long-continued 
multiplication by means of soredia. 
In Beitrag zur Kenntniss der Chytridiaceen, Dr. Nowakowski 
gives an account of the life-history of the iaglonc-qiar taba studied 
already by Baill, A. Braun and Schenk, to bsesape he gives the name 
Polyphagus Euglena The organism appears in the form of globular 
colourless cells between resting Euglena individuals, from the surface 
of each of which are soon given out four cruciate or several radiate 
immeasurably fine threads, which elongate until they come in contact 
e 
g top. , live at the expense of th r. A thre 
which has chanced to enter a Euglena becomes larger than its fellow 
and club-sh i oe of the Pisa: supplied by the 
host, the parasite continues g (one sig growth being the for- 
mation of secondary bran ens on nfo tse. siteadasy and the nucleus 
wit h it was originally provided entirely disappears fter a 
ter 
anism peneitiy of a system o anne branched pa = 
greenish-yellow and then brownish. Reproduction by zoospores 
was observed at the end of April. The zoosporangia are formed 
by protoplasmic outgrowths from the side of the thickened body of 
the parasite ceoeee and are at first not covered by a limiting 
ES they are of O¥al or a eaas figure, and when fully 
. After swimmin g about for an sa or so the e to rest, 
_. a globular form, and send out Acjneta-like scsi | of which 
mention was made in commencing; they are now, in fact, ready to 
commence depredations on any resting Euglena they may happen to 
come in contact with. The author has also observed sexual reproduc- 
tion, which takes | by means of smooth-membraned resting- 
resulting from copulation between a femal ent consisting of a 
rmine the sex before copula- 
contents e male 
, which consists in the blending of 3 the ent 
nent with those of the female w holly extruded in th form of a8 
* 
rere Piro Ay PL aN 
