1894 THE MICROSCOPE. 23 



other so all have well-defined qualities which unmistak- 

 ably mark them as a separate branch of creation. These 

 characteristics may be stated as follows : 1, on the ex- 

 terior of the body are many, more or less minute, open- 

 ings — pores for admitting water into the interior, and 

 one or more larger openings — oscuIsp —for emitting 

 water from the interior without any other exterior or- 

 gans ; 2, the animalcule or colony of animalcules is con- 

 cealed in the interior without any contact with the ex- 

 terior : 3, the animalcule has a collar and fiagellum. 



Pores. — These exist in innumerable quantities, and 

 can generally be contracted. What causes the influx of 

 water has not been sufficiently ascertained. Some spe- 

 cies have been observed with ciliary motion at the pores, 

 but this has not been proved sufiiciently. It may be 

 possible that the natural pressure of the water surround- 

 ing the sponge may cause it, without any artificial effort 

 to enter the body no matter how small or narrow the 

 pores. No matter how, the fact is water does enter, and 

 this fact upon the slightest consideration becomes one of 

 great interest and another proof of nature's marvelous 

 adaptability of means to ends. Of course the use of the 

 water is clearly apparent and is the same as for all in- 

 fusorian food. However, hoto this water is used is an 

 interesting question. It passes through the internal 

 canal system, the food particles it contains are taken up 

 and the remainder, together with the faecal matter, is 

 ^ent into larger canals out through the external larger 

 orifices called, wrongly, oscuht. As these osculae might 

 with their polluted contents taint the inflowing water, 

 they are arranged according to the growth of the sponge : 

 where upward these osculsp" stand elevated above the 

 pores ; where downward, as hanging on rocks, even with 

 pores, as in such case the matter sent out naturally will 

 leave the sponge. 



In a live active sponge the inflow through the minute 



