80 Natural History of British Zoophytes. 
veloped into polypes in the lateral denticles and extreme cells. Such 
was the deduction he came to from observations made on the growth 
more especially of the Sertularia abietina, which he had kept alive 
for nearly four months in a vessel of sea water. When a new part 
was formed, there first emerged from the stem a minute tubular 
joint, which rose to four, five, or even eight lines in height : after 
some days some lesser buds, regularly disposed in an alternate man- 
ner, were seen on the sides of this branch, which in the course of 
four or six days grew into cells containing perfect polypes. Hence* 
it is obvious to Baster that the stem of this and similar zoophytes 
grows in thickness and length as plants do, and that the medullary 
pith is animal, which it is not wonderful should assume a dendroi- 
dal form, when we see zinc and quicksilver do the same by the mere 
force of affinity. Trembley had already pronounced the cells of the 
fresh-water zoophytes (Plumatella) to be not the work of the po- 
lypes, but rather compartments in which they concealed a part of 
their body ; and this fact, added to those already given, makes it 
certain that the animalcules of the Sertulariadse are entirely pas- 
sive, and have no more to do with their polypidoms than the flower 
has with the increase and growth of the herb. * 
There is some ambiguity in Easter's statement of his opinions, 
for it is not very obvious whether he believed the new formed branch- 
lets to be themselves the eggs or seeds, or whether they only con- 
tained the eggs ; but be this as it may, it appears scarcely doubtful 
that he knew nothing of the true ova and their curious ovaries. 
The phenomena observed in the production of new parts are cor- 
rectly stated, but nothing but wilful prejudice could blind him to 
the fallacy of the consequent reasoning. The analogy attempted to 
be drawn between the eggs of zoophytes and the seeds of plants 
has no existence, for every tyro knows well that the coat or skin of 
seed in no instance ever pushes forth radicle fibres, or ever exhi- 
bits any sign of vegetation ; it is a dead part which is cast off or 
corrupts, and exerts no further influence on vegetation than as a 
protection to the cotyledons and embryo which it invests, so that if 
it is true that the coat of the ova of zoophytes is the source of their 
vegetative part, as Baster says, that coat must be of a very differ- 
ent nature from the skin of seeds. It would have been better to 
have compared the oviform bodies of the zoophyte with the buds of 
Jtegtree, and he might have disported with this fancy to some ef- 
fect, for there are many analogical resemblances, and the inapplica- 
* Phil. Trans, vol. lii. p. 108-118 For Easter's works see Hall. Bib. Bot. 
i. 468. 
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