M. C. COOKE ON MICROSCOPIC MOULDS. 69 



advocate perhaps a Lieberkuhn, or similar mode ; my own impres- 

 sion certainly is that we are deficient in the means of viewing 

 opaque objects satisfactorily with a quarter-inch. I must confess 

 that I can do no good with a Lieberkuhn on a quarter-inch ; per- 

 haps I may be a bungler. One great objection which I have, for 

 my purposes, to modern and good English high powers, lies in the 

 quantity of metal which the makers give us. A small nozzle is 

 required, the smallest possible, so that with side reflectors and 

 condensers we might get light, whereas usually there is greater 

 breadth in the quarter-inch than in the inch, hence we get more 

 light with the German powers, because the "nozzle" is smaller. (If 

 I may use such an undignified term as " nozzle,") I would suggest 

 to some spirited maker the manufacture of a quarter-inch with the 

 smallest possible diameter at its extremity, so that all those who, 

 like myself, believe in objects seen as they are, without having the 

 light thrown through them, may gratify their depraved (?) tastes. 



And now, as to the examination of moulds in the best way we 

 can, under existing circumstances with high powers. A smaller 

 portion, consisting of but two or three flocci carefully removed, and 

 placed on a glass slip, covered and fastened clown forthwith without 

 the slightest movement of the glass after it has touched the object, 

 will sometimes give a moderately good slide for the quarter-inch. 

 The heads of spores will be broken or distorted, and other allow- 

 ances will have to be made ; but this is the only way in which I 

 have been able to make out the structure, for instance, of the 

 sporophores of such a mould as Botryosporium. 



The " Black Moulds " and some other of the Hyphomycetes are 

 far less delicate than the Mucedines, and many of these, as 

 Helmintlwsporium and Macrosporium, might be mounted in balsam, 

 although I think that very few indeed of the Microscopic Fungi are 

 not much better in diluted glycerine — the cover being fastened down 

 with gum dammar dissolved in benzole — than when mounted in 

 that medium, in Deane's gelatine, or in balsam. Some persons 

 have a mania for balsam, but it is clear to me that the miserable 

 collapsed spores and threads of specimens mounted in balsam, 

 when I had less experience, are only caricatures of the things 

 themselves in a state of nature, or even when preserved in diluted 

 glycerine. 



Already I find that my remarks must close without reference to 

 a very important subject, which it was my intention to have in- 



