NOTES AND MEMORANDA. 147 



mycelium may affect different modes of development, as in the two 

 examples cited by Hoffmann. The concrete mycelium or sclerotium 

 is rather scattered amongst the Agarics, as the remarkable researches 

 of Leveille have demonstrated it, and removed all doubts on the 

 subject. In his recent work,* M. Tulasue gives a rather instructive 

 history of Sclerotium, which appears to be most complete on the 

 subject. 



M. Leveille has indicated the mode of sclerotial formation, which 

 has greater analogy with the rhizome, as is remarked in Agaricus 

 fusipes ; the base of the pedicel is permanent, and produces the 

 following year some new Agarics, becoming more or less branched. 

 The mycelioid nature of the Sclerotium, and its assimilation to the 

 organs which, in the Phanerogams, take the place of veritable stems, 

 is a proof more in favour of the theory, first noticed by Palissot de 

 Beauvois, and then by Dutrochet, of the identity of the mycelium with 

 a stem of thallus. 



NOTES AND MEMORANDA. 



Herr Gegenbaiier, now at Heidelberg^. — Dr. Gegenbauer, of 

 Jena, the well-known Comjiarative Anatomist, has been nominated 

 ordinary Professor of Anatomy and Director of the Anatomical In- 

 stitute in the University of Heidelberg. 



Crystals in the Seed-coat of the Elm (TJlmus campestris). — 

 ' Science Gossip' (August) says that at this season, or a little earlier, 

 the fruit of the elm is shed and scattered in profusion on the ground, 

 often so as to make patches in our paths. Each fruit is a capsule, 

 somewhat oval, very flat, and about as big as the thumb-nail. The 

 seed is contained near the centre of this comj^ressed and winged 

 capsule or samara, and the outer coat of the seed is the seat of the 

 crystals. Every cell of this part contains a short and brilliant crystal, 

 in form cubical, lozenge-shajjed, or prismatic, and presenting a long 

 diameter of about ^^-g-th, and a short diameter of 3 A - th of an inch. 

 They are beautiful microscopic objects, and perhaps may be found 

 well adapted for exjjeriments with polarized light. The crystals are 

 composed chiefly of oxalate of lime. 



An American Criticism on Dr. Maddox's Simple Mount. — This 

 we cannot allow to escape us, though it appeared some time since, 

 the fact being that we have only now had our attention directed to it. 

 The writer in the ' Lens ' says that anything coming from Dr. Maddox 

 in the microscope line may be anticipated to be good, and no one can 

 be surprised that he says, " It works quickly, easily, has considerable 

 range, and no sensible slip." By slip he undoubtedly means what 

 the mechanic terms back-lash ; a fault that is so annoying to the 

 microscopist, and almost universally found in objectives imported from 

 Europe. Hundreds of American microscopists will confirm Dr. 

 * ' Selecta Fungorum Carpologia,' p. 107. 



