416 
P. A. POTTS. 
we may expect to find reproducing individuals differing 
widely in length. 
The principal interest lies in the two specimens which are 
producing stolons (VIII and IX). In the individual from 
Port Townsend, described by Johnson, the stolons wei’e about 
fifty in number, arising from the right-hand border of the last 
segments of the stock. Thirteen of them had attained an ad- 
vanced stage of development (with twenty to twenty-eight seg- 
ments — 2'5 mm. in length). “ To the right at the base of the 
cluster is a group containing about twenty-five very young buds 
as yet showing no segmentation, but each with the two distal 
processes which are the anal cirri.” “ The buds are arranged 
in rows, partly transverse and partly longitudinal as regards 
the axis of the stock.” “In a graduated series, proceeding 
from the left side of the cluster of youngest buds, are more 
advanced buds, the lai’gest approaching the mature con- 
dition.” 
It is evident that Johnson’s individual was characterised by 
very asymmetrical development of the proliferating patch. 
No. A^III of my collection (PI. 23, fig. 2) resembles his in all 
essential particulars, but it will be noticed that the zone of 
proliferation occupies an entirely median position, and the 
stolons are at first arranged in perfectly transverse rows, the 
members of which are all equidly developed, even to sharing 
a lateral twist, which directs the tails of all the stolons in one 
row to the right and to the left in the next. 
As the stolons increase in size and breadth the outer mem- 
bers of the row are pushed more and more to the side, and 
also anteriorly, because of the presence of the rows behind, 
so that the row becomes a crescent, and the proliferating 
region is partly surrounded by stolons in advanced develop- 
ment. Irregularities jnust, however, frequently occur owing 
to inequalities of growth. The asymmetry of Johnson’s speci- 
men, it appears to me, is due, firstly, to the lateral appearance 
of the patch of proliferation, and, secondly, to distortion, due 
to unequal growth of the members of the different rows, 
which have had more room to grow on the left of the stock. 
