22 
HISTORY OF ZOOPHYTOLOGY. 
or new branches, which fall off on maturity, and adhere to any 
stone, shell, or other hard body, by which they are protected 
until the young are excluded. Now the outer coat of this egg 
or seed is of a vegetable nature, and it throws out from the sides 
in the manner of other seeds, certain little roots by means of 
which it remains permanently attached ; but the internal part 
of the egg or seed is animal , and growing simultaneously with 
its vegetable covering, it is dispersed through all the ramifica- 
tions and occupies their hollow interior, being developed 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 mi- 
nute tubular joint, which rose to four, five, or even eight lines 
in height: after some days some lesser buds, regularly dispos- 
ed in an alternate manner, were seen on the sides of this branch, 
which in the course of four or six days grew into cells contain- 
ing 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 dendroidal 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 polypes, but 
rather compartments in which they concealed a part of their 
body ; and this fact, added to those already given, makes it cer- 
tain 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 Baster’s statement of his opinions, 
for it is not very obvious whether he believed the new formed 
branchlets to be themselves the eggs or seeds, or whether they 
only contained the eggs ; but be this as it may, it appears scarce- 
ly doubtful that he knew nothing of the true ova and their cu- 
rious ovaries. The phenomena observed in the production of 
new parts are correctly stated, but nothing but wilful prejudice 
* Phil. Trans. Vol. lii. p. 108-118. — For Baster’s works see Hall. Bib. Bot. 
i. 468. 
