May 10, 1907] 



SCIENCE. 



723 



{Acris grylhis) with the skin covered but 

 eyes exposed reacted like normal frogs; 

 without the use of the eyes their responses 

 corresponded to those of the earthworm. 



We have thus a physiological test of the 

 image-forming powers of the eyes, and in 

 these experiments it corroborated in the 

 main inferences which would be drawn 

 from a study of the structure of the eyes 

 in question. 



This paper is published in Proc. Am. 

 Acad. Arts and Sciences, Vol. 42, No. 16, 

 pp. 335-417, Jan., 1907. 



The Significaiice of the Grasping Antennce 

 of Male Harpacticoid Copepods: L. "W. 

 Williams, Harvard Medical School. 

 This paper has been published in Sci- 

 ence for February 8. 



Further Ohservations on the Behavior of 



Tubicolous Annelids: Chas. W. Haegitt, 



Syracuse University. 



Following up the work done on these 

 animals and reported elsewhere, the writer 

 has extended the observations to aspects of 

 behavior other than those already recorded. 

 Three points are concerned in the following 

 observations : 



First, a study of behavior under natural 

 conditions of environment. This has been 

 possible in quiet pools near low tide lines. 

 Experiments on Hydroides dianthus with 

 shadow stimuli, or light intensity of vary- 

 ing degree, under these conditions have 

 confirmed in all essentials those made last 

 year. 



Experiments as to tactile responses 

 showed considerable variations as com- 

 pared with the former series. This may 

 be attributed to the fact that specimens 

 living under these conditions become more 

 or less inured to similar stimuli from the 

 actions of waves which naturally buffet 

 them almost constantly. 



Second, experiments on the relative sen- 

 sory acuteness of specimens from deep 



water, about twenty fathoms, compared 

 with those from shallow waters, one to 

 three or four fathoms. In cases tested 

 there was shown a definite preponderance 

 of positive reactions among the latter, and 

 a corresponding preponderance of negative 

 responses in the former. 



Third, a comparative study of the as- 

 pects of behavior shown in the growth of 

 colonies taken from shore waters, subject 

 to the action of waves, and those from 

 quiet waters of bays, etc., shows an un- 

 mistakable variability in the aspects of 

 the tubes, which clearly indicates environ- 

 mental adaptation. Furthermore, speci- 

 mens growing in an environment, such as 

 marly bottom, or silt, or other similar con- 

 dition, show the same evident response of 

 adaptation. On the other hand, specimens 

 growing along shore lines, or on rocky bot- 

 toms, show likewise the unmistakable re- 

 sponse natural to such condition. Not a 

 single colony among hundreds along the 

 shore lines showed any free and vertical 

 tubes. Likewise specimens dredged from 

 muddy bottoms showed the erect and ver- 

 tically directed tubes which would bring 

 the animals above the obstructing mud. 



Any careful consideration of the facts 

 would hardly fail to convince one that no 

 single factor, such as heliotropism, or geo- 

 tropism, or any other tropism alone, was 

 adequate for their explanation. 



Rhythmical Pulsation in Animals: Alfred 

 G. Mater, Carnegie Institution of Wash- 

 ington. 



Experiments made at the Tortugas Ma- 

 rine Laboratory of the Carnegie Institution 

 upon Cassiopea, Salpa, Lepas and the log- 

 gerhead turtle give results as follows : 



Ehythmical pulsation can be sustained 

 only when a strong stimulus is counter- 

 acted by an inhibitor, so that the pulsating 

 organism is maintained at or near the 

 threshold of stimulation in a state analo- 



