No. 490] NOTES AND LITERATURE 



megalocephala bivalens; and that in the hybrids there may be an 

 extraordinary disturbance in the number of chromosomes, the laws 

 and the explanation for which are not apparent. 



Methods and PubUcations.— Dr. R. M. Yerkes of Harvard Uni- 

 versity exhibited apparatus for testing color vision and the delicacy 

 of visual discrimination in mice. Similar boxes are illuminated 

 either by photometered lamps of different intensity or by colored 

 lights. Over the floors of the boxes are wires for an interrupted 

 electric current whereby the animal receives slight shocks when it 

 enters the wrong box. The value of the apparatus is in its complete 

 elimination of sensations other than those which are being tested. 

 Under the title "The dancing mouse; a study in animal behavior," 

 the MacMillan Company has in press a collected account of Dr. 



Mrs. S. P. Gage of Ithaca, New York, showed her method of making 

 models from sheets of blotting paper instead of plates of wax. The 

 outline of the section is drawn upon the paper and may be cut out by 

 the needle punctures from an unthreaded sewing machine. The 

 blotting paper is then soaked in melted paraffin, and tho smoothing 

 of the surface, after the model has been ]mt t()<,M'tlicr, is done with 

 paraffin. Pins are inserted, as in wax modrls, tor stahiliiy. The 

 resulting model is light and less fragile tliaii those made of wax; it is 

 not liable to change its shape in warm weather, or to erack by the 

 expansion of metal supports. 



Professor G. A. Drew of the lUiversiiy ..f Afaiiie .howe.l a method 

 of making a series of anatomical (h-awitiixs for reprixhieiion hy the 

 zinc process. That part of the 111 is to ajipear in several 



drawings is drawn first, and photographed ni)oii suitable paper. 

 The figure is then completed by using pen and ink upon tlie photoiirapli. 

 Thus the organs may be drawn and photo<;'ra plied, ami four fi<:tires 



up upon this background. ProtV>sor Drew used tlie ineiliod in iiiakin<: 

 his drawings of Pecten. 



Dr. IT. H. Field of Ziirieh exhiluied a eompl.'te >eries of the ear.l 



