330 H. MORLAND ON MOUNTING DIATOMACE^. 



being that I am more exacting than I nsed to be. My object is 

 not now to fill my cabinet, but simply to get perfect slides if 

 possible, and this cannot be done unless care be exercised. I am 

 by no means infatuated over slides containing scores of diatoms, 

 but comparatively few species, many of the valves being found 

 to be dirty and clogged when examined under a moderately 

 high power, say a J-inch, and the whole pattern of which can 

 only be seen under a very low power, a 2-inch or 3-inch, quite 

 unsuitable for examining the diatoms themselves. Moreover, 

 there is no special difficulty in mounting such slides, for if any- 

 one can arrange a dozen diatoms properly, there is no limit to 

 the number he can so arrange, it being merely a question of 

 time, without, to my mind, a corresponding compensation. 



I have endeavoured, as far as possible, to shorten this paper 

 without sacrifice of utility. Many of the minutiae I have 

 described may seem of but small moment, but neglect them, 

 and the difference will be that between a good mount and a 

 very imperfect one. Haste is far too often the cause of failure, 

 but when our work has to be, as it were, superhypercritically 

 examined under high power objectives with high numerical 

 apertures, it behoves us to do our very very best, so that our 

 work may come out scathless through the ordeal. 



