175 
its affinity with Plasmodiophora and named it Plasmodiophora 
Alni. Woronin * then reviews Miller’s article and states that it 
yet remains to be shown whether this Plasmodiophora-\ike para- 
siteis the sole cause of the root galls, or whether, perhaps, as he 
already had suggested? it was accompanied by a filamentous 
fungus. 
Brunchorst,t by his excellent investigations, gets the key to 
the true nature of the parasite and thus fairly sets in order a sub- 
ject hitherto clouded in great confusion. The fungus is shown to 
be a filamentous one and what Woronin§ and Méller|] took to be 
Spores are in reality sporangia, which by successive oblique 
divisions of the protoplasmic contents form spores. 
The plasmodia of various authors is the cell plasma of the 
host with the very fine fungus threads imbedded in it and so 
obscured that they cannot be seen except by the use of certain 
reagents. Thus with the use of a hot solution of “ Salzsaure” 
in galls from Alnus glutinosa, a delicate filamentous structure, 
reminding one of a skein of matted threads, is made visible. . 
In longitudinal sections of a gall, he calls attention to three 
rather ill-defined zones, representing different stages of develop- 
ment of the parasite. Just behind the root-cap is the first zone, 
bearing the younger stages of the fungus, where in fresh untreated 
Preparations it resembles plasmodia. . Next comes the Sporae 
sum zone, where the hyphe can be seen quite well, bearing _ 
their ends at the outer surface of the hypha-skein the sporangia. 
In the third zone the contents of the sporangia are. either under- 
80ing division into spores, or are empty. ie. 
The likeness of the fungus in the younger zone to plasmodia 
* Berichte der Deutschen Botanischen Gesellschaft, Bd. III, 1885, Pp. 177; 
t Compte rendu de la séance mensuelle du 10 Jan., 1890, de la nopienen 
de botanique Belgique. See also Revue Mycologique, Tome U., 1880, P- 69, 79, 
and Bot, Centralblatt, 1880, p. 354. 
Uche; die Knollchen an den Wurzeln von Alnus und den Elzagnaceen. 
t. Centralblatt, XXiv, p. 222, 1885. 
ae einige Wi diisncd a. besonders diejenigen von Alnus und 
den Eleagnaceen, Unters. Bot. Inst. Tiibingen, Zweite Band, 
See also Bot. Centralb, Bd. xxviii, p. 109, 1986. 
$Mem. Acad, Imp. Sci., etc. 
| Bericht, Deut., Bot. Gess, 
p- 151, 1886. 
