454 



SCIENCE. 



[N. S. Vol. III. No. 64. 



longs.to the subfamily Helorinse of the Procto- 

 trypidae. L. O. Howaed, 



Recording Secretary. 



NEW YOBK ACADEMY OF SCIENCES — BIOLOGICAL 

 SECTION, FEBRUARY 7, 1S96. 



Dr. J. G. Curtis in the Chair. 



A communication from the Council was re- 

 ceived asking that the Section take action 

 on Representative Hurley's bill " To fix the 

 standard of weights and measures by the adop- 

 tion of the metric system of weights and 

 measures." 



On motion of Dr. Dean the Section approved 

 the bill, and the Secretary was directed to ex- 

 press the entire commendation of it to the 

 Council. 



Dr. Arnold Graf read a paper on ' The Struc- 

 ture of the Nephridiap in Clepsine.' He finds 

 in the cells of the intra-cellular duct fine cyto- 

 plasmic anastamosing threads which form a con- 

 tractile mechanism. These are stimulated by 

 granules which are most numerous near the 

 lumen of the cell, and thus a peristalsis is set up, 

 which moves the urine out of the duct. In the 

 upper part of the intra-cellular duct the two or 

 three cells next to the vesicle or funnel have no 

 distinct lumen, but are vacuolated ; the vacuoles 

 of the first cell being small, those of the second 

 larger, and so on, till the vacuoles become per- 

 manent as a lumen. He explains the action of 

 the first cell as being similar to the ingestion of 

 particles by the infusoiians. The matter taken 

 up thus from the funnel by the first cell is car- 

 ried by the rest, and so on till the cells having a 

 lumen are reached. The presence of the excre- 

 tum causes the granules to stimulate the mus- 

 cular fibres of the cells; peristalsis results and the 

 substance is carried outwards. The character 

 of this contractile reticulum offers an explana- 

 tion of the structure of a cilium as being the con- 

 tinuation of a contractile reticular thread. 



N. R. Harrington, in ' Observations on the 

 lime gland of the Earthworm,' described the 

 minute structure of these glands in L. terres- 

 tris, and showed that the lime is taken up from 

 the blood by wandering connective tissue cells 

 which form club-shaped projections on the 

 lamellae of the gland, and which pass ofi" when 

 filled with lime. The new cell comes up from 



the base of the older cell and repeats the pro- 

 cess. This explanation is in harmony with the 

 fact that in all other invertebrates lime is laid 

 down by connective tissue cells. Histological 

 structure and the developmental history con- 

 firm it. 



Dr. Bashford Dean offered some observations 

 on ' Instinct in some of the lower Vertebrates.' 

 The young of Amia calva, the dogfish of the 

 Western States, attach themselves, when newly 

 hatched, to the water plants at the bottom of 

 the nest which the male Amia has built. They 

 remain thus attached until the yolk sac is ab- 

 sorbed. As soon as they are fitted to get food 

 they flock together in a dense cluster following 

 the male. When hatched in an aquarium they 

 go through the same processes. The young 

 fry take food particles only when the parti- 

 cles are in motion, never when they are still. 

 The larvae of Necturus also take food particles- 

 that are in motion. C. L. Bristol, 



Secretary. 



NEW YORK ACADEMY OF SCIENCES. 



At the meeting of the Section of Astronomy 

 and Physics held on March 2, 1896, the election 

 of officers for the ensuing year was held, and R, 

 S. Woodward was elected Chairman and W. 

 Hallock Secretary. 



The first paper of the evening was upon the 

 device designed by Prof. W. L. Robb for show- 

 ing the way in which a cord can vibrate, con- 

 sisting essentially of an electro-magnet running 

 a vibrating arm to the end of which the string 

 is attached. 



The second paper was upon a new form of 

 polariscope, designed by Prof. A. M. Mayer, 

 consisting of a special arrangement of crossed 

 lenses, resulting in unusually good illumination 

 and large field. 



The next paper was upon a heliostat de- 

 signed by Prof. Mayer. In this connection Prof. 

 Mayer called attention to the shortcomings of 

 the various forms of heliostats, and especially 

 those using only one mirror, pointing out, 

 among other things, the useless width of mirrors 

 on such heliostats, and illustrating what ought 

 to be the dimensions of such a mirror. He also 

 called attention to the great advantage of using 

 sunlight for all optical experiments over any 



