124 Transactions of the Royal Microscoincal Society. 



to ride his own hobby, whether that be " diffraction phenomena," 

 or any other ; only he must take care that his hobby do not throw 

 him. But Dr. Woodward has ridden his hobby at a pace which 

 will hardly be salutary for his reputation. If his theories be 

 correct, and if the results of assisted vision be so utterly untrust- 

 worthy, what becomes of the microscope as an aid in scientific 

 research ? or is his meaning only, that microscopists on this side of 

 the Atlantic must not presume to publish any opinion without 

 licence first obtained under his broad seal, but must in all cases 

 telegraph their doubts to Washington, and wait in patience for the 

 Washington imprimatur ? 



I think also that his suggestion, that men of such eminence as 

 Eabenhorst, Lindig and Seibert are incapable of steering clear of 

 so well known an obstruction as diffraction, is — to put it mildly — 

 in questionable taste. 



Indeed, it would seem as though Dr. Woodward cared more 

 on which side of the Atlantic a thing is said, than for the statement 

 itself. 



In Mr. G-. W. Morehouse's article " On Microscopic Powers," * 

 we read : " First-class |ths to sVths are showing the transverse 

 striae of Amphipleura pellueida, NavicuJa crassinervis, Frustidia 

 Saxonica, and Nitzschia curvula. The sVth reveals longitudinal 

 lines on all these, much finer than the transverse, and evidently 

 genuine. Under favourable conditions the resolution into the so- 

 called beading is distinctly effected on the first three named." 

 And in another article, contributed to the ' American Naturalist,' 

 and reprinted in the ' M. M. J.,'t the same gentleman says : "Frus- 

 tulia Saxonica. In addition to my observation of longitudinal 

 lines upon this test and resolution into dots, it may be worth noting 

 that, even with lamp illumination, the ^^^ has displayed the 

 transver,-e much clearer than they appear in Dr. Woodward's photo- 

 print. J This is one of the most difiicult test diatoms thus far 

 studied, ranking but little easier than A. pellueida, N. crassinervis, 

 and Nitzschia curvula." It will be seen here that Mr. Morehouse 

 has anticipated me in saying all I had to say in my letter 

 of last July, and has said it with more particularity. He has 

 not only seen genuine longitudinal lines on Frustulia Saxonica, 

 but has resolved them into dots. He further states that the longi- 

 tudinal lines are " much finer than the transverse." He also, — as 

 do all men who know anything about the matter, — regards Frustulia 

 Saxonica as not identical with Navicula crassinervis; and, that 

 there might be no mistake as to the tendency of his remarks, he 

 has expressly referred to Dr. Woodward's paper in the ' Lens.' 



* ' M. M. J.,' vol. X., p. 150. 



t Vol. xii., p. "l'^. 



X ♦Lens,' vol. i., p. It)?. 



