ANIMAL LIFE IN PONDS & STREAMS 



closely related to the bell animalcule, known by 

 the name of Carchesium Spectahile, We cannot fail 

 to recognise its family likeness to the form we have 

 already studied, for it consists of a large number 

 of stalked bells growing on a single parent stem. 

 It is really a little colony of bells. When one of the 

 young individuals of Carchesium settles down in the 

 spot it has selected for its dwelling-place, it grows 

 a stalk just as Vorticella did, and it divides later into 

 two individuals. Now in Vorticella only the bell 

 divides, in Carchesium part of the stalk divides also 

 and, instead of swimming away to find a new home 

 it remains attached to the parent stalk. When this 

 has happened several times a goodly colony is 

 formed. 



There are few fresh-water animals more common- 

 place and apparently uninteresting when observed 

 casually than the pond sponge and the river sponge. 

 Yet, if we take either of them home and examine 

 them with the aid of our microscope, we shall be 

 delighted with our specimens. In reality they are 

 of absorbing interest and, at certain times of the 

 year we may easily obtain young sponges, and 

 capital objects they make for the microscope. 



Before we describe our two specimens let us try 

 to explain what manner of creature a sponge really 

 is. If we examine any bath sponge, we notice that 

 it is perforated with many small holes and some 

 larger ones. Some sponges show this better than 

 others. The small holes are pores, the large ones 

 mouths, but, as we shall see in a moment we must 



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