408 
he used in studying his parasites characteristic each of its 
disease magnified only 250 diameters, and that the methods 
of isolation were incomplete. But he was a German, and 
so the English believed in him at first. The Rev. M. J. 
Berkeley, who is probably a sounder observer, but who has 
not caused so much c sensation’ as Hallier, also studied the 
subject of the fungoid origin of disease, and in his address at 
Norwich 1 he expressed the opinion, based on his great know- 
ledge, that Hallier had gone farther than the facts warranted, 
and was simply wrong. Most people are swinging back (like 
the pendulum) to this opinion, although we hear occasionally 
of remarkable confirmations of Hallier’ s views from America 
and elsewhere. 
Cell-diagnosis in plants has yet to be made of its full value. 
Professor Gulliver has studied the Raphides in many, and 
shown how far they furnish characters. He has lately written 
on pollen-grains, hut more remains to be done, especially as 
to hairs, pollen-grains, and starch-granules, which may fur- 
nish important systematic characters. In animals, minute 
points of structure have been used by the systematist with 
advantage, and may be still more so. The setse of Annelids, 
requiring a good quarter for their proper discrimination, so 
delicate are their forms, characterise genera and species ; the 
odontophore of cephalous Molluscs, the shell structure of 
Brachiopods, the blood-corpuscles of the Yertebrata, are 
examples of structures which furnish important diagnostic 
characters when studied with the microscope. It is obvious 
that this use of the microscope has a very different aspect to 
that of histology. The systematist is not an anatomist, and 
looks at the differentife of structure rather than the relations 
and resemblances. 
Of the Forensic and Technical aspects of microscopical 
science we have not now space to speak. 
With regard to the instrument, we would most strongly 
urge the importance of British microscopists fully under- 
standing and appreciating the powers and value of the instru- 
ments used in other countries. We mean especially as to the 
objectives. Colonel Woodward, of the United States Army 
Medical Department, has done great service for us by com- 
paring many powers in resolving Nobert’s lines ; but other 
tests of efficacy besides resolution of lines should be applied 
if possible. If Nachet’s immersion lenses are better, or as 
good, as the best of our long-boasted English glasses, let us 
know it and buy them, since they cost about half the price 
1 See this Journal, October, 1868. 
