128 SELECTED XoTES FROM 



Filaria Bronchialis. -This is very different to the worm that 

 I have taken from the throats of cliickens and known as the 

 " Gapes." 1 think the scientific name of the Gape worm is 

 Sderostonia sy//x'd///us. S. A. Brenan. 



Bulgaria inquinans is figured and described on p. 732 of 

 '"Cooke's Handbook of Brit. Fungi," iSyijand is there said to 

 be found on Oaks, etc. John Ford. 



Spiral and Scalariform Vessels. — Sections of Fern show the 

 Fitter arrangement. Spiral vessels may easily be seen by 

 partly cutting through many vegetable structures, such as 

 the stalk of a Geranium leaf, and then breaking and draw- 

 ing the divided portion asunder. If not too deeply cut, the 

 parts are held together by the stretched spiral vessel, the rings 

 of which had been lying in close apposition. Both forms of 

 vessels are beautiful under the microscope, 



J. D. Brown. 



Halo Slide. ^ — I do not know what fungus was the parent 

 of the spores contained in this slide, but I have been told that the 

 spores of the Truffle when mounted have a similar effect. I 

 suppose the effect is owing to the spores, and not to the medium 

 in which they are mounted. To see the effect well there should 

 be only one small light in the room, as the flame of a candle or 

 small gas jet, and the light should be looked at through the object 

 at a distance of about 10 feet. G. D. Brown. 



Halo Slides. — These slides are prepared from the spores of 

 'Iruffle (probably Tnbcr cibarium). Truffles are more common in 

 this country than is generally supposed. In the contributor's 

 slide the spores, being unripe and tolerably transparent, appear to 

 have been mounted diy. But in a " Halo " slide, by the same 

 preparer, in my own possession, I observe the spores are a dark 

 brown, and appear to be mounted in balsam, and in this latter the 

 diffraction spectra are very much larger, brighter, and more 

 numerous. Probably this curious optical effect would be j)roduced 

 by the sporangia of other fungi, such as those of Lycoperdon (the 

 Puff-ball). Hastily glancing over my cabinet of Cryptogams, I 

 find several slides which show the so-called " Halo," notably one 

 of Lycopodium sporules, in w^hich the circular iridiscence is par- 

 ticularly fine. As to the cause of this, it would be difficult, if not 

 impossible, to pen any short exjjlanatory note which would be in- 

 telligible to those unacquainted with the laws and varied phe- 

 nomena of diffraction. One of the best popular works of reference 

 on the subject is Lommell on Fight (King and Co., 5s.). All those 

 who use either Microscope or Telescope may study this section of 



