120 KANSAS UNIVERSITY SCIENCE BULLETIN. 



corroborate his statements if possible. To make the arguments 

 still more conclusive, in addition to the work upon Ambystoma, 

 I made a few measurements and drawings of the chromosomes 

 of Gryllus. If Meek's theory can be established as a law which 

 will hold throughout the animal kingdom it will be of inestimable 

 value. 



MATERIAL AND METHODS. 



The material for the study of both Ambystoma and Gryllus 

 domesticus was prepared in the laboratories of Kansas University. 

 The Ambystoma was fixed in Flemming's Fluid and stained with 

 Heidenhain's iron-haematoxylin. The slides for the Gryllus were 

 kindly loaned me by Prof. W. J. Baumgartner. These were all 

 fixed in Flemming's fluid; some were stained with iron-haema- 

 toxylin and some with Flemming's triple stain. 



The preparations were studied by means of a Leitz apochro- 

 matic oil immersion T V a objective and a No. 4 ocular and a 

 No. 18 compensating eye piece. The source of illumination for 

 most of the work, and especially for the measurements and draw- 

 ings was ordinary daylight projected upon the mirror of the 

 microscope by means of a funnel made of heavy black paper in- 

 serted in other heavy paper which covered the greater part of the 

 window, thus admitting only a small amount of light between the 

 shade and the heavy paper. Part of the work was done by gas 

 light with a Welsbach burner, the rays passing through a copper 

 sulphate solution. 



The drawing board was built on a level with the microscope 

 stage. The measurements and drawings were made by the aid 

 of an Abbe camera lucida, so adjusted that the center of each 

 measurement and each drawing was 100 mm. from the center of 

 the objective. The measurements were all made with the draw 

 tube adjusted so that the distance from the drawing table to the 

 upper part of the ocular was 231 mm., thus giving a magnification 

 of 4000 diameters. The drawings were made with the draw tube 

 adjusted so that the distance was 211 mm., giving a magnification 

 of 3200 diameters. The drawings represented in the plate here 

 are reproduced at 2145 diameters. The magnifications were de- 

 termined by means of a Zeiss stage micrometer. 



OBSERVATIONS. 



It will not be necessary to go into details concerning the early 

 prophase of mitosis as that has already been dealt with by other 

 investigators. By a count of the chromatin knots and the chro- 

 mosomes of the telophase, and especially of the metaphase, I find 



