162 Journal of the Mitchell Society [ December 
leave it an open question whether the masses of teased tissue 
were able to regenerate the sponge body. 
During the past summer’s work at the Beaufort Laboratory 2 
I again took up this question and am now in a position to 
state that the dissociated cells of silicious sponges after 
removal from the body will combine to form syncytial masses 
that have power to differentiate into new sponges. In Micro- 
ciona, the form especially worked on, nothing is easier than 
to obtain by this method hundreds of young sponges with 
well developed canal system and flagellated chambers. How 
hardy sponges produced in this artificial way are and how 
perfectly they will differentiate the characteristic skeleton, 
are questions that must be left for more prolonged experimen- 
tation. 
Taking up the matter where it had been left at the end of 
the preceding summer, I soon found that it was not neces- 
sary to allow the sponge to pass into a degenerative state, 
but that the fresh and normal sponge could be used from 
which to obtain the teased out cells. Again in order to get 
the cells in quantity and yet as free as possible from bits of 
the parent skeleton, I devised a substitute for the teasing 
method. The method adopted is rough but effective. 
Let me briefly describe the facts for Microciona. This 
species (M. prolifera Verr.) in the younger state is incrust- 
ing. As it grows older it throws up lobes and this may go 
so far that the habitus becomes bushy. The skeletal frame- 
work consists of strong horny fibers with embedded spicules. 
Lobes of the sponge are cut into small pieces with scissors 
and then strained through fine bolting cloth such as is used 
for tow nets. A square piece of cloth is folded like a bag 
around the bits of sponge and is immersed in a saucer of fil- 
tered sea-water. While the bag is kept closed with the fin- 
gers of one hand it is squeezed between the arms of a small 
pair of forceps. The pressure and the elastic recoil of the 
21 am indebted to the director of the station, Mr. H. D. Aller, for his 
kindly aid in supplying all facilities needed in the course of my investi- 
gation. 
