Vol. XLIV April, 1923. No. 4. 



BIOLOGICAL BULLETIN 



MOTOR REACTIONS OF THE FRESH-WATER SPONGE, 



EPHYDATIA FLUVIATILIS. 1 



GEORGE T. McNAIR, 

 Hull Zoological Laboratories, The University of Chicago. 



Parker's work on Stylotella heliophila ('10) has suggested the 

 possibilities of similar experiments with fresh-water sponges and 

 a comparison of the reactions of the two types. 



Aside from Parker's monograph practically nothing has been 

 published on the motor reactions of sponges. Dr. R. E. Grant 

 (i825-'26) published a series of papers on the "Structure and 

 Functions of Sponges," which are of historical interest only. 

 He quotes an earlier paper (Ellis and Knight, Transactions of the 

 Royal Society of London, 1765), in which these men stated that 

 they had seen the orifices on the surfaces of sponges contract and 

 dilate themselves. Grant studied a large number of salt-water 

 species, both in their natural habitat and in the laboratory. 

 He was the first to notice and accurately describe the currents of 

 water coming from the fecal orifices (oscula) and spoke of them 

 as mysterious currents because he could not learn what caused 

 them. He irritated the orifices and other tissues with corrosive 

 acids, red hot wires, etc., but under no circumstances did he see 

 the osculum closed and erroneously concluded that there was a 

 complete lack of irritability and contractility, attributing the 

 statements of Ellis and Knight concerning the "systole and 

 diastole of the fecal orifices" to "some optical deception a little 

 assisted by the imagination." 



Parker made two types of experiments on Stylotella, noting 



1 The problem was suggested to me by Dr. W. J. Crozier. It is with great 

 pleasure that I acknowledge my indebtedness to him and also to Professors C. M. 

 Child and W. C. Allee for their helpful suggestions and criticisms. 



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