STOLON FORMATION IN SPECIES OF TRYPANOSYLLIS. 441 
stances. This no doubt goes some way to explain the “large 
size and heavy form” which Johnson noticed in T. gem mi- 
para, suggesting' “ that they are somewhat sluggish in their 
habits,” but it would no doubt be erroneous to suppose that 
tlie aberrant method of reproduction was due to the habitat, 
for Haplosyllis, with its simple method of reproduction, is 
likewise a sponge-dweller. We can, indeed, say that the habit 
of stolon reproduction in the Syllids generally is partly due to 
the sheltei'ed and isolated localities they inhabit, but to 
attribute any extreme form of this to a particular habitat 
would be rash. 
For the present the problem of collateral budding in T. 
gemmipara and the other species must remain almost 
isolated. But two circumstances help us to form some idea of 
its origin. The first is the formation of the genital appendage 
and its occasional separation as a stolon, which points to the 
derivation of T. gemmipara from a species like T . kroh n i i , 
in which a single stolon is formed at a time, from the posterior 
segments of the stock. The second is the occurrence in this 
O 
latter species of a kind of ventral budding from the exti'emity 
of the stock to form a second stolon. A full description of 
this remarkable phenomenon (see 5, pp. 20-22) is out of place 
here, but it seems to me that an exaggeration of the tendency 
might Avell result in the production of a number of ventral 
stolons, while the retarded formation of the first stolon would 
give rise to the organ described here as the “genital 
appendage.” 
Rkmarks on T. Misakiensis Izuka (4). 
Only a single individual of this species has been obtained 
and I am not certain that a sufficient case has been made out 
for separating it from T. gemmipara. Its length, breadth 
and number of segments fall easil}”- within the limits recorded 
for T. gemmipara. In two other important points — the 
presence of bidentate ventral setae and the chai-acter of the 
head and eyes — the two species agree exactly. Notes on the 
coloration were not preserved and the account of the struc- 
