SPONGES Qy 
GENEOLOGY OF SPONGES. 
The following is my idea of the derivation of sponges, from vegetables 
through the Protozoa. This is illustrated by the figure of a geneological tree. 
Fig. 42 ; 
The roots are vegetables, one of which to the left, represents Plant Ani- 
mals, and thisis partly beneath the surface, A ,A, and partly above it where 
are some incipent shoots. 
From the roots arise the Protozoa, First Animals. On the right is sent off 
a branch which grows downward, the degraded and parasitical Gregarinida. 
minute animals foind in earth worms. Above this, branch out the class Mon- 
era, from which arise two groups, the Vampyrella and the Protomyxa, bril- 
liant in color, but very simple in structure. 
Opposite, on the left,is the class Rhizopoda from which branch well 
known forms, Amoeba, Foraminifera, Halizoa and Radiolaria. Above these 
branches, continues the main trunk asclass Infusoria. From this arise two 
strong branches : on the right, order Cilliata, from the base of which springs 
the class Coelentreata which continues the life series upward, and on the left. 
t he order Flagellata, from the base of which arises the Province Poriferae or 
sponges. This continues as Silicious Sponges, giving off twigs above, as 
Fleshy and Horny, and below as Limy, and further on as Fresh Water. 
It will thus be seen that in the upward advancement of the Geneological 
Tree, sponges are pushed one side on a branch by themselves just-as various 
branches of the Protozoa are given out. In other words, ascending forms of 
fife did not pass through all of these types of Pretozoans and lower forms of 
