SPORE-FORMATION IN THE DISPORIC BACTERIA, 587 
“Tie seltene Ausnahme hiervon . . . dass namlich zwei 
Sporen in einer Kinzelzelle gebildet werden, kann in einem 
Uebersehen der Scheidewand zwischen zwei sporenbildenden 
Zellen ihren Grund haben.” This view has been held by the 
majority of other writers. I may mention, however, that 
Ernst (1888) described and figured certain cases in Bacillus 
xerosis in which two spore-rudiments were present, without 
any signs of a septum between them ; and that Frenzel (1892) 
found unmistakable cases of the existence of two spores in 
his very large “griiner Kaulquappenbacillus.”! From the 
size of this organism, it seems to me unlikely that the septum 
—had it been present—would have been overlooked. 
As far as I am aware, no other Bacteria which normally 
forms two spores have ever been described—and up to the pre- 
sent the process has been observed in detail in B. biitschlii 
and B. flexilis alone. 
GENERAL CONCLUSIONS. 
Schaudinn’s interpretation of the phenomena observed in 
B. biitschlii was that the fusion of the two incompletely 
a) 
separated “daughter’’-cells (text-fig. B, A 2, 5) represented 
a degenerate process of conjugation. A conjugation of this 
sort has been shown to take place in the yeasts (Schidnning, 
Hoffmeister, Janssen and Leblanc, Guilliermond) ;* in the 
diatom Achnanthes subsessilis (Karsten) ;* and in Pro- 
tozoa, of which perhaps Actinospherium furnishes the 
best example (Hertwig).* Conjugation of adjoining cells is 
' This organism is of considerable interest in the present case, for it 
is another gigantic—occasionally disporic—form from Anura (tadpoles 
—probably of Bufo marinus). Frenzel describes the formation of 
the spore from a central nucleus-like body, but I think he was mistaken 
when he described the disporic forms as arising through the previous 
division of this body. 
* See Barker, ‘ Annals of Botany,’ vol. xv, 1901. 
3 See Klebahn, ‘ Arch. Protistenk,’ Bd. 1, 1902. 
4 R. Hertwig, ‘ Abh. Akad. Miinchen,’ xxix, 1898, 
