Boycd Microscopical Societtj. 3 



scribed will be readily made out, particularly as they do not 

 require at all a high power for a general view of them. The 

 modern ^th of Powell and Lealand, which is a superb objective, 

 shows these small columns distinctly as I have drawn them in 

 Fig, 5 of Plate II., but they can be well seen with a Beck's |th, 

 which is so good as to bear a D eye-piece most satisfactorily. I 

 wish it to be understood that I am not advocating the use of low- 

 power objectives and high-power oculars in a general way, but 

 now and then, as in the objects in question. Such an arrangement 

 has its advantages, inasmuch as the low-power objective allows 

 us to see a greater number of planes in focus, and so to get the 

 general shape and relative position of an object which we can 

 afterwards examine in detail, with all the fine definition obtainable 

 by a deep objective and shallow ocular. 



I hope I have not been wearisome in the description of these 

 columnal elevations in the ribs of the battledore scales. The ex- 

 amination may seem trivial — time apparently thrown away upon 

 an insigniiicant object, but the investigation has a value in this, if 

 in nothing else, as showing that we must not take for granted 

 that we know all about a structure, because it presents certain 

 appearances when viewed in one position. Also, we must not lose 

 sight of the fact, as we re-observe our weU-known objects with our 

 magnificent modern appliances, that, though our glasses are vastly 

 improved, yet they are still far from perfect, and that probably 

 those who come after us in examining these same objects, may give 

 a half-pitying smile at what we thought we saw, and still more at 

 what we failed to see. 



B 2 



