No.1.] BUDDING IN GOODSIRIA AND PEROPHORA. 159 
colonies. Fig. 1, Pl. XII, represents a colony, natural size, grow- 
ing on a laminaria leaf. As here seen, the zooids are, as com- 
pared with many compound Ascidians, rather distant from one 
another. They are very regularly distributed, there being no 
suggestion of systems. Neither have the zooids any constant 
relation either to the colony as a whole or to one another, with 
reference to their antero-posterior axes; though in general 
where the colonies are narrow and elongated the longer axes 
of the zooids correspond to the longer axes of the colonies. 
The arrangement of the adult zooids is of course determined 
by the relations which the developing buds hold to their 
parents, and in this there appears to be no constancy beyond 
the fact that the buds are generally confined to the borders of 
the colonies. I say generally this is the case; but it is not 
without exception, for in several instances I have found young 
blastozooids so situated that older ones intervened between 
them and the edge of the colony. (Fig. 2, Pl. XII.) 
The question of the relation of the buds to the older zooids 
is important because it obviously involves the questions whether 
all the zooids of a colony are capable of producing buds, and 
at what age in the life of the zooids their buds are produced. 
And this last question leads back again to the fundamental 
one of whether or not the cells that initiate the bud-develop- 
ment are derived as unmodified or embryonal cells from the 
parent, the grandparent, and so on to the sexually produced 
embryo that was the common ancestor of the colony. What 
I have to say on this point will be better reserved until I 
speak in detail of the Axlage of the bud, my purpose here 
being to describe merely the form and composition of the 
colony as a whole. In a few instances (Fig. 2, buds a and 8), 
for example, there is a suggestion that at the borders of the 
colonies the younger buds occupy positions alternating with 
the next older ones, but a little in advance of them toward the 
edge of the colonies. If, however, such a law of arrange- 
ment exists, it prevails less frequently than do the exceptions 
to it. 
To Metchnikoff’s (69) denial that buds are produced by the 
vessels in Botryllus, Giard ('72) raises the objection that if this 
