WOODWARD, ON NOBERT S TEST-PLATE. 



227 



No. of band. 



o 

 O 



4 

 5 



6 



7 



8 



9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18- • 

 19 



aris line 



No. of lines to 



the millimeter. 



886 



1108 



1329 



1550 



1773 



1994 



2215 



2437 



2658 



2880 



3101 



3323 



3544 



3766 



3987 



4209 



4430 



It will be seen that the lines of the 15th band of this plate 

 are the same distance apart as those of the 30th of the thirty- 

 band plate, and those of its 11th band are the same distance 

 apart as those of the 20th band in the twenty-band plate de- 

 scribed by Mr. Beck. 



Max Schultze* has published a short account of some ob- 

 servations made by him with one of ihese new nineteen-band 

 plates, from which it appears that with central ilkimination 

 he succeeded in resolving the ninth band with tw^o objectives, 

 viz., Hartnack's immersion system No. 10 and Merz's im- 

 mersion system ^V* By oblique light he was able to see the 

 true lines in the 14th band. Mr. Charles Stodder,t in a re- 

 cent article on the Nobert plate, quotes the abbreviation of 

 Schultze's article in the ' Quarterly Journal of Microscopical 

 Science,' January, 1866, as follows : — " With oblique illumi- 

 nation he has not been able with any combination to get 

 beyond the 15th." This, I think, is hardly what was in- 

 tended by Schultze's somewhat ambiguous remark, "Bei 

 Schiefem Licht bin ich mit den besten systemen bis zur 

 15ten gruppe gekommen," which I understand to mean 

 that he resolved the 14th band, getting thus as far as to the 

 15th, which he did not resolve ; an interpretation which is 

 confirmed by the quotation made by Mr. Stodder in the same 



* ' Archiv fiir Mikroskopische Anatomie,' erster band. Bonn, 1865, p. 

 305. 



t " Nobert's Test-plates and Modern Microscopes." 'American Natu- 

 ralist/ vol. ii, p. 97. 



